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Presents an investigation of the sequencing of 65 amino acid residues at the carboxyl-terminus. Use of methods such as enzymic or chemical cleavages of the peptide chain; Fractionation of peptides by Sephadex or Dowex column chromatography, paper elctrophoresis or chromatography.

Semihemoglobins α and β are derivatives of human hemoglobin which possess the usual chain composition (α2β2 or αβ) but which carry the heine prosthetic group on only one kind of chain (α or β), the complementary chain (β° or α°) being heme-free. In this paper, new results on two compounds of this type, namely, semiHbαD (αβ°) and semilHbβ (α°β) have been presented; existing data on other earlier preparations have also been reviewed. Methods for preparation of semiHbαD and semiHbβ have been described-. Some of their properties including optical absorption, circular dichroic spectra, oxygen equilibrium and kinetics of carbon monoxide binding have been measured; these properties are then compared with those possessed by intact hemoglobin (β2β2), isolated chains (α,β) and the berne-free apoprotein (α°β°). 1. The contribution of the heine moiety to the optical absorption and circular dichroic spectra of the semihemoglobins are found to be intermediate between those of hemoglobin and those of the corresponding isolated chain. This result indicates that the effect of interaction between the unlike chains of these molecules are transmitted as far as the heine prosthetic group. The structure of the heme-free chain is also modified as the result of this interaction as revealed by titration of sulfhydryl groups, although circular dichroic spectra in the far ultraviolet are not conclusive. 2. The oxygen affinity and the Bohr effect of the semihemoglobins are again intermediate between those of hemoglobin and isolated chain, the semiHbβ being closer to hemoglobin than semiHbαD. The same is true concerning the velocity of carbon monoxide binding. 3. The kinetics of fixation of carbon monoxide to semihemoglobins is strongly biphasic. It is suggested that this property could reflect the existence of semihemoglobins as two types of filmers (αβ) but differing among themselves on account of different contact regions brought into play. (α1β1 and α1β1 in the nomenclature of Perutz.) 4. The significance of the fact that semiHbα is obtained in multiple forms is considered. 5. The ensemble of the results are discussed in the context of chain-chain interactions. [ABSTRACT FROM AUTHOR]

In this paper the metabolism of amino sugars in the retina and in the pigment epithelial cells has Been studied. Extracts obtained from the retina and from the pigment epithelial cells are capable, in the presence of suitable cofactors, of converting [1.14C]glucosamine into UDP-N-acetylhexosamines. Chromatographic investigations with the use of Dowex resin column have permitted the identitication of the principal intermediaries of amino sugar metabolism: GlcNAc, GIcN-6-P, Glc-NAc-6-P, UDP-GlcNAc, UDP-GalNAc. Both the retina and the pigment epithelial cells are, further, capable of synthesizing those amounts of acetyl coenzyme A necessary for the formation of acetylated amino sugars. The metabolism of amino sugars in the retina would appear to be much more active than in the pigment epithelial cells; this would indicate that the greater part of the synthesis of mucopolysaccharides of the interstitial matrix takes place in the retina. In the course of this research, furthermore, the presence of three compounds has been ascertained, the identification of which is still in progress. [ABSTRACT FROM AUTHOR]

The porcine anti-dinitrophenyl antibody was subjected to affinity labeling by m-nitrobenzenediazonium fluoroborate. From the S-sulfo derivative of the labeled antibody light (λ and ...) and heavy chains were isolated. It was found by spectral analysis of the polypeptide chains that the m-nitrobenzenediazonium reagent labeled tyrosine residues. In the light chains 10% molecules, in the heavy chains 21% molecules were labeled. Tryptic digest of labeled λ-chains was resolved by gel chromatography. The label was found to be distributed in two peasks at a ratio of 7: 3. From the labeled peptides of the tryptic digest shorter peptides were prepared by hydrolysis with subtilisin and purified by gel chromatography, paper chromatography and affinity chromato- labeled se peptides with known sections of the amino acid sequence of the λ-chains of porcine nonspecific immunoglobulin showed that the main portion of the label is attached to the tyrosine in position 33, s lesser portion to the tyrosine in position 93. [ABSTRACT FROM AUTHOR]

Specific antibodies to two plant, hormones, namely indole-3-acetic acid and gibberellic acid, were produced in rabbits which were immunized with conjugates of either hormone to hemocyanin. The specific antibodies obtained were used for assaying the hormones by several immunological assays. The most sensitive assay reported in this paper, for the determination of indole-3-acetic acid and gibberellic acid, is the inhibition of inactivation of modified bacteriophage. For this assay conjugates of either hormone with bacteriophage T4 were prepared and characterized. Such chemically modified bacteriophages were completely inactivated by the respective specific antiserum and this inactivation was inhibited by the free hormone. The specificity of the antibodies produced was tested by a series of cross-reactions. There was no immunological cross-reaction between the two hormones which can, therefore, be determined independently. However, antibodies to indole-3-acetic acid cross-reacted with chemically related compounds such as indole-acetyl-ε-amino caproic acid, tryptamine and tryptophan. The immunological specificity of different gibberellins tested was found to be in good correlation with the biological specificity. [ABSTRACT FROM AUTHOR]

A direct reading, six channel conductivity recording apparatus has been constructed and used to assay enzymes, including some of those found in muscle. This paper gives the essential theory of the method, and indicates that it is a highly versatile assay system. It may be applicable whenever ionic substrates are involved, but this is more easily tested by experiment than by calculation. The manipulation involved in an assay is probably less than in any other method. Conductimetry could be used as a kinetic method for some enzymes (for example amidases), but suffers from restrictions in the amounts of non-reacting ionic species which can be tolerated. Improvements in the temperature control of the apparatus could allow much higher sensitivity to be used. [ABSTRACT FROM AUTHOR]

The effect of trypsin treatment with respect to the allosteric properties of yeast phosphofructokinase as well as its molecular weight has been studied. In the presence of fructose 6-phosphate trypsin desensitizes yeast phosphofructokinase to ATP inhibition. Under the same conditions, activation of this enzyme by the positive allosteric effector AMP, however, remains uneffected. Addition of MgATP instead of fructose 6-phosphate to the incubation medium containing trypsin protects the enzyme against ATP-desensitization. After prolonged incubation of yeast phosphofructokinase with trypsin the enzyme becomes inactivated both with fructose-6-phosphate and with MgATP. Using density gradient centrifugation sucrose media the effects of trypsin treatment on the sedimentation behaviour of yeast phosphofructokinase has also been investigated. With fructose 6-phosphate, trypsin converts the 560000 form of yeast phosphofructokinase into two enzymatically active forms of 510000 and 350000 daltons respectively, which are both e to ATP inhibition. On the other hand, in the presence of MgATP the peak of enzymatic activity sediments with 160000 daltons. This molecular form has the same high sensitivity to ATP inhibition as the untreated enzyme of molecular weight 560000. After the addition of fructose 6-phosphate, the 160000-molecule seems to dimerize giving an ATP-sensitive form with a molecular weight of 340000. In the light of studies about the existence of several interconvertible forms of yeast phosphofructokinase published recently by our laboratory, the results described in this paper are discussed in terms of the existence of dimeric and trimeric states, regarding the 16000-moiety as the trypsin modified monomer of the enzyme. Kinetic and allosteric properties of these states including conditions for their formation and stabilization are summarized and the peculiarities of the trypsin-unmodified and trypsin-modified enzyme are compared. [ABSTRACT FROM AUTHOR]

The partial specific volume of chymotrypsinogen A in water and aqueous urea solutions has been determined from density measurements. The partial specific volume of the protein first increases with urea concentration, reaches maximum, decreases, reaches minimum, and then increases again. An interpretation of this behavior has been attempted considering especially the binding of urea to the protein and imperfect atomic packing in the native protein. From dilatometric experiments the differences between the partial molar volumes of the protein in water and urea solutions of different concentrations, respectively, have been obtained. The agreement of the values of these differences with those calculated from the partial specific volumes is satisfactory. It can be seen that the volume changes reflect the interaction of urea with the protein which eventually results in complete unfolding, i.e., denaturation, in about 8 M urea. Subsequent papers will deal with further aspects of this denaturation. [ABSTRACT FROM AUTHOR]

An immunoglobulin M from Waldenström's disease (IgM Ga) was hydrolysed by papain and a glycopeptide fraction was isolated by gel filtration on Sephadex G-100. This fraction was then successively resolved into fourteen glycopeptides by gel filtration on Sephadex G-50 and by preparative paper electrophoresis at pH 1.9. The amino acid and carbohydrate content of these glycopeptides was determined by ionexchange chromatography in an autoanalyzer. All of them contain aspartic acid and serine, but they are quite different from one another, in amino acid composition and sequence about, the carbohydrate-peptide linkage, especially with respect to histidine, tyrosine, threonine, valine, glutamic acid, lysine and proline. Furthermore, a number of glycopeptides contain only mannose and glucosamine, while others contain in addition, galactose, fucose, and N-acetylneuraminic acid, in variable amounts. These results suggest the presence of several linkage sites of the oligosaccharide chains on the H-chain and the true heterogeneity of these oligosaccharide chains. The peptide sequence of a few glyeopeptides was reported, especially the following: r-Asn(carbohydrates)-Ser-Thr, also present, in the Fc fragment of Immunoglobulin G. [ABSTRACT FROM AUTHOR]

Our previous studies [1,2] on maleyl bovine αS1-B casein were concerned with the isolation and amino acid composition of the tryptic peptides designated as Tm peptides. The sequence of the COOH-terminal Tm peptide containing 48 residues was also reported. In the present study, we report the overlaps of all the cyanogen bromide peptides as well as the Tm peptides from αs1-B casein. The αs1-B casein which contains five methionyl residues was cleaved with cyanogen bromide. The six expected peptides obtained by this treatment and designated as CN peptides, were separated initially on Dowex-50X2 and further purified by Sephadex column chromatography. The amino acid composition of these six purified CN peptides was determined. The results were in perfect agreement with the amino acid composition of αs1-B casein deduced from the analysis of Tm peptides. The three Tm peptides from αs1-B casek@ which contained methionyl residues were also cleaved by cyanogen bromide. The fragments obtained were purified by either paper chromatography or Sephadex column chromatography and the amino acid composition of these purified peptides was determined. Of the eight peptides thus obtained, three were found identical with the CN peptides obtained directly by BrCN treatment of the αs1-B ease@. The remaining three CN peptides from αs1-B casein for which identical fragments could not be located fun the Tm peptides, were digested with trypsin (in two eases after maleylation) and the resulting fragments were purified by Sephadex column chromatography. These trifle peptides provided the remaining gaps. This permitted in to locate the relative position of all the CN peptides in the αs1-B casein molecule. These results also indicate the location of all the Tm peptides except 2 in the αs1-B casein molecule. Further, the chymotryptic peptides from one of the CN fragments of αs1-B casein provided the missing overlaps. [ABSTRACT FROM AUTHOR]

Our earlier publications on the primary structure of bovine αs1 casein, which contains 198 amino acid residues in a single polypeptide chain, dealt with the sequence of forty-eight residues from the COOH-terminal and also with the various approaches utilized for the elucidation of the primary structure of the molecule: amino acid composition of tryptic peptides, composition and arrangement of the peptides obtained by selective hydrolysis at the arginyl or methionyl bonds and identification of the tryptic peptides in these two series of peptide fragments. In the present communication we report the sequence of sixty amino acid residues from the NH2-terminal of the bovine αs1 casein with the exception of a fragment consisting of seven amino in our final publication. The NH2-terminal of bovine αs1 casein contains markedly different zones which are successively basic (position 1 to 10), non-polar (position 20 to 33) and acid (position 45 to 60). We will report in another paper that the A variant of αs1 casein is characterized by a deletion of thirteen amino acid residues in the part of the NH2-terminal. [ABSTRACT FROM AUTHOR]

1. 1. Acapsular (K-) forms were isolated from Escherichia colt strain E56b (serotype O8 :K27(A): H-). A number of different R strains were obtained from the K- forms by selection of spontaneous mutants and by phage selection. 2. The lipopolysaccharides of these R strains (consisting of core and lipid A) were subjected to mild acid degradation and, after removal of insoluble lipid A, the mixtures were fractionated by gel chromatography. Results of chemical analyses showed that the core oligosaccharides of different R mutants differed with respect to their sugar constituents as well as to the molar ratios of these constituents. A group of R mutants did not contain phosphate in their core oligosaccharides (P- mutants). Enzyme determinations indicated that one R mutant had a block involving UDP glucose pyrophosphorylase, whereas the enzymes of activation and interconversion of component sugars were intact in the other R mutants. 4. By allelic exchange (mating with S-form Hfr strains)it could be demonstrated that with one exception the chromosomal site of the S→ R mutation of all mutants maps close to mtl (mannitol utilization). In Salmonella the rfa locus maps fun the same region. All R mutants had an unimpaired (his-linked) rfb locus. 5. The groups of mutants which differed in the sugar composition of their core oligosaccharides could also be differentiated serologically and by their sensitivity to phages. There was serological cross reactivity between the lipopolysaccharides of some R mutants with R mutants of Salmonella minnesota which also have a very incomplete core. It is concluded that the lipopolysaccharides of the R mutants described in this paper have incomplete core structures which result from blocks at successive stages in the synthesis of the coli R1 core. in analogy to Salmonella these E. coli R mutants shoed, with one exception, be termed rfa type mutants. [ABSTRACT FROM AUTHOR]

Ornithine carbamoyltransferase from Halobacterium salinarium is a typical extremely halophilic enzyme. It is rapidly and irreversibly inactivated when exposed to a salt-free environment and shows high activity at NaCl concentrations above 4 M. The present paper describes the purification of the enzyme from cell free extracts, by acetone fractionation, gel filtration, sucrose gradient centrifugation and chromatography on calcium, phosphate gels. All purification procedures were carried out on 4.3 M NaCl solutions to prevent irreversible inactivation of the enzyme. Ornithine (0.1 M) stabilizes the enzyme and was included throughout the purification. The purified enzyme was essentially homogeneous as judged by polyacrylamide gel electrophoresis and by analytical ultracentrifugation. Enzyme activity was measured as citrulline formation from ornithine and carbamoylphosphate in the presence of 4.3 M NaCl, at 37°. Specific activity of the purified enzyme was about 1 µmole citrulline formed per minute per µg protein or an about 50-fold increase from that of cell-free extracts. Halophilic enzymes which can not be reactivated from a salt-free environment have not previously been extensively purified. [ABSTRACT FROM AUTHOR]

Chemical investigation of the glycosidic constituents of Oospora virescens (Link) Wallr. resulted in the isolation of several glycosides. We have shown recently that two of them, named virescenoside A (I) and B (II) are β-D-altropyranosides of virescenol A and B; these diterpenic aglycones have been found to have the structure of isopimaradien-α,3β-19-triol (JV) and isopimaradien-3β,19-diol (V), respectively. In this paper we describe the isolation and structure of virescenoside C, a new metabolite of Oospora virescens. The results obtained show that virescenoside C (IIIa), C26K40O7, m. p. 160-162°, [α]D -71,4Y°, is a β-D-altropyranoside of virescenol C, which is found to have the structure of 3-keto 19-hydroxy isopimaradiene (VIa). These results are based on physical evidence (infra-red, nuclear magnetic resonance and mass spectra) and particularly on the chemical correlation with virescenol B and virescenoside B. Virescenoside C seems to be the third example of an altroside found in nature, [ABSTRACT FROM AUTHOR]

1. Tryptic hydrolysates of denaturated glutamic-aspartic transaminase fractionated on a Sephadex G-25 column, gave an elution diagram containing six main fractions. When peptide maps were developed from the transaminase digest 37 spots were detected on the paper sheet. 2. It was demonstrated that the transaminase fractions (groups of peptides) as well as some of the individual peptides eluted from the map spots, possessed immunological activity. This was proved by theft capacity to interact with rabbit pig heart antienzyme and rabbit antiserum against the pig-heart whole tryptic transaminase hydrolysate as well as to inhibit the homologous transaminase-antitransaminase reaction. Higher immunological reactivity was found among peptides moving faster in electrophoresis and chromatography. 3. The catalytic activity of rabbit transaminases (heart, liver, skeletal muscles), was inhibited to a substantial degree by the rabbit anti-pig heart transaminase. The above enzymes however. as was otherwise expected, gave negative precipitin reactions with antitransaminase. A comparative study of the reactivity between transaminases from pig, ox and rabbit and rabbit antitransaminases against pig and ox heart enzymes as well as against pig-heart whole tryptic transaminase hydrolysate is presented here. [ABSTRACT FROM AUTHOR]

1. Tryptic hydrolysates of denaturated glutamic-aspartic transaminase fractionated on a Sephadex G-25 column, gave an elution diagram containing six main fractions. When peptide maps were developed from the transaminase digest 37 spots were detected on the paper sheet. 2. It was demonstrated that the transaminase fractions (groups of peptides) as well as some of the individual peptides eluted from the map spots, possessed immunological activity. This was proved by their capacity to interact with rabbit pig heart antienzyme and rabbit antiserum against the pig-heart whole tryptic transaminase hydrolysate as well as to inhibit the homologous transaminase-antitransaminase reaction. Higher immunological reactivity was found among peptides moving faster in electrophoresis and chromatography. 3. The catalytic activity of rabbit transaminase (heart, liver, skeletal muscles), was inhibited to a substantial degree by the rabbit anti-pig heart transaminase. The above enzymes however, as was otherwise expected, gave negative precipitin reactions with antitransaminase. A comparative study of the reactivity between transaminases from pig, ox and rabbit and rabbit anti-transaminase against pig and ox heart enzymes as well as against pig-heart whole tryptic transaminase hydrolysate is presented here. [ABSTRACT FROM AUTHOR]

The experiments reported in this paper lead to the following conclusions: 1. An endonucleolytic activity is associated with the "replication site" in Escherichia coli cells; this endonucleolytic activity attacks the complementary strand of the ψx replicative form DNA only. 2. the viral strand of the ψx-replicative form DNA remains circularly closed during the replication cycle; 3. In the immediate replication product both composing strands are linear; in circularization no strand is preferred; 4. A replication product with both strands closed is transiently found in a structural state which can be, under our experimental conditions, only partially denatured by alkali. Subsequently it is transformed to a typical supercoiled RFI structure. [ABSTRACT FROM AUTHOR]

In order to determine the primary structure of the bovine β-caseins, the A2 variant was first cleaved with trypsin and cyanogen bromide (CNBr). The tryptic hydrolyzate was separated by column chromatography on Dowex-50. After additional purifications, 13 peptides numbered Ti to T13 were isolated. The 14th tryptic peptide, T14, not eluted from the column, was directly obtained from the hydrolyzate by preparative paper electrophoresis. Amino-acid analyses were carried out on all these peptides. Peptide T1 contain 2 Arginyl residues, one of which is NH2-terminal. This peptide represents the NH2-terminal end of the β-casein. Its composition is identical to that reposed by Peterson et al. in 1958 [1] for a phosphopeptide isolated from the β-casein. Peptide T11 contains 2 Lysyl residues, one of which is NH2terminal. The COOH-terminal peptide was identified with peptide T4, devoid of basic aminoacids. The 14 tryptic peptides account for all the residues of the β-casein A2 when compared with the already published amino-acid analyses of the whole protein [2, 3]. Several other peptides, originating from incomplete or non-specific cleavages, were also obtained. Similarly, 7 peptides accounting for the 6 methionyl residues of the protein were obtained from the same variant of β-casein after cleavage with cyanogen bromide. Six of these peptides were separated on Sephadex G-50. The seventh peptide was obtained by chromatography on Dowex-50 of the whole CNBr-digest. After additional purifications, the ammo-acid compositions of the 7 pure peptides were determined. Peptide CN1 contains peptide T1. It represents the NH2terminal end of β-casein. The COOH-terminal end of β-casein was identified with peptide CN7. As in the case of the tryptic peptides, the 7 CNBr-peptides account for all of the amino-acid residues of β-casein A2. β-casein A2 has 208 amino-acid residues. Its molecular weight is very close to 24 000. [ABSTRACT FROM AUTHOR]

Further evidence is presented in this paper concerning the occurrence of three different molecular species of acetyleholinesterase in the electric eel's electric organ. These species, A, C, and D, differ in their sedimentation coefficients (8.5 S, 14.2 S, and 18.4 S, respectively). We show that the whole of the tissue acetyleholinesterase activity can be solubilized by repeated homogenisation, in the form of A, C, and D. Homogenisations under different conditions of ionic strength, or after prolonged autolysis yield closely similar results: the ratios of A, C, and D are remarkably constant. Moreover ammonium sulfate precipitation does not affect these species. This raises the question of their relationship and significance. All three species are recognized by antibodies obtained from rabbit immured against the purified enzyme. We have also studied the solubilization of acetylcholinesterase by trypsin in electric tissue slices. This is very effective and directly yields species B. This species, which is homogeneous in sedimentation, but might contain a variety of slightly different protein molecules, can also be obtained by partial tryptic digestion of A, C, and D, The sedimentation coefficient of species B is very close to that of purified acetylcholinesterase and we have previously suggested that the two kinds of molecules may be similar. Even though this is probably correct, we have been able to detect a significant difference (0.8 S unit) in the sedimentation coefficients. [ABSTRACT FROM AUTHOR]

A previous paper described the amino acid composition of the fragments resulting from selective cleavage of the bovine αS1-casein polypeptide chain at arginyl bonds after blocking the lysyl residues by maleic anhydride. The fragment Tm2, which is 48 residues long, represents the COOH-terminal part of the αS1-casein chain, according to the following observations: (a) it is devoid of arginine; (b) only the peptide Tm2 is colored by the Ehrlich reagent specific for Tryptophane; (c) the two amino acids released by carboxypeptidase A (successively Tryptophane and Leucine) are those of the COOH-terminal end of αS1-casein. The complete sequence of this large COOH-terminal peptide obtained from αS1-casein C was determined by classical methods, using endopeptidases to produce smaller peptides, then exopeptidases and the Edman sequential degradation procedure for establishing the amino acid sequence of these peptides. A part of this work has been published in a previous communication reporting the location, at the eighth position from the COOH-terminal end, of the substitution Gly/Glu between the genetic variants αS1C and αS1B. [ABSTRACT FROM AUTHOR]

Under standard assay conditions, the replicative DNA polymerase partially purified from rat liver non-histone chromosomal proteins exhibited a marked preference for native DNA over heat-denatured DNA as the template. However, work reported in the present paper demonstrates that this template preference could be reversed by changing the enzyme to template ratio in the assay system. This change in template preference was observed when either the concentration of DNA polymerase or of DNA was varied. Furthermore, it is shown that this alteration in template specificity is not the direct result of the action of an alkaline endonuclease present in the DNA polymerase preparation. [ABSTRACT FROM AUTHOR]

The complex formation between copper(I) ions and glycylglycylglycine (H2A+) has been studied in 3.0 M NaClO4 medium at 25° by constant current coulometry using copper amalgam and glass electrodes. In each series of measurements the copper iota were generated into the ligand solution by electrolysis of two phases copper amalgam. The data, shown in Table 2, were treated by graphical methods and by the least squares computer program, Letagrop. It is concluded that the results obtained are consistent by assuming the equilibria Multiple line equation(s) cannot be represented in ASCII text. where β is an equilibrium constant. It is assumed that the copper(II)-equilibria, reported in the previous paper of this series, coexist in solution. On the bask of the equilibrium constants it may be deduced that for pH higher than 6.5 the principal copper(I) complex is CuICuIIH-3A22-. The standard oxidationreduction potential at pH 7 for the formation of this species from its copper(II) analogue, Cu2H-4A22-, was calculated to be +340 mV. [ABSTRACT FROM AUTHOR]

It is well know that protein synthesis stopped either by chloromycetin or by starvation of an essential amino acid for a RC relstrain, ribosomal RNA synthesis continues, but products do not appear in 50 S and 30 ribosomes. It has also been shown that 5 S RNA synthesis is altered by the addition of chloromycetin but in an unknown manner. In this paper we report that: (a) during amino-acid starvation of a starvation of RCrel strain of Escherichia coli, 5 S RNA is transcribed as 5 S relax RNA located outside the ribosomes, in the supernatant fraction; (b) this 5 S RNA which is slightly longer than the normal product is convertible into a true 5 S RNA when protein synthesis is restored after blockage of RNA synthesis by actinomycin ;(c) part of the 23 S RNA from a 25 S particle appears after resumption of protein synthesis in a 40 S parcel which contains normal 5S RNA; (d) a pool of 5 S precursor RNA exists outside the 50 S ribosome. This 5 S precursor RNA is isolated; (e) this precursor which is isolated from the 105000xg supernatant fraction after pulse labeling, migrates on gel electrophoresis between 5 S relax RNA and true 5 S RNA. [ABSTRACT FROM AUTHOR]

The interspecific hybrid Arbacia lixula ... × Paracentrotus lividus ... which stops developing at the onset of gastrulation, was previously found to contain much more DNA of maternal origin (P. lividus) than DNA of paternal origin. In spite of this, the RNA synthesized by the blocked gastrula hybridizes better with DNA of paternal type than with DNA of maternal type. An explanation of thru observation was sought in the present paper by means of saturation and competition experiments. The higher affinity of RNA from the hybrid gastrula for paternal DNA could be due to the fact that RNA of paternal type is complementary to a longer portion of the corresponding DNA than RNA of maternal type. This explanation was not satisfactory since the number of genes of paternal type which are active in the hybrid is not very different from the number of genes of maternal type. In normal embryos of A. lixula and P. lividus, RNA from unfertilized eggs and from plutei was found to be less competitive against labeled RNA from gastrulae than gastrula RNA itself. Transcription of the genome is therefore partially stage-specific. This stage-specificity is maintained in the hybrid as far as transcription of the maternal genome is concerned, but is lost as far as transcription of the paternal genome is concerned. The hybrid gastrula was shown to synthesize more RNA molecules of A. lixula type than does the normal gastrula of this species, whereas RNA of P. lividus type is produced in equal amounts m normal and in hybrid embryos. These observations explain the hybridization properties of the RNA synthesized by the blocked gastrula. The results suggest that the genes of paternal type that are very active in the hybrid are those genes which m normal embryos are transcribed at all stages of development and probably also in the adult. This class of genes is much more active in a foreign cytoplasm than in the cytoplasm of its own species. On the other hand, the genes whose activity is restricted to the gastrula stage m normal embryos are not active in the hybrid. This class of genes does not seem to function in a foreign cytoplasm. [ABSTRACT FROM AUTHOR]

1. The distribution of ribosomal particles between the soluble and membrane fractions of exponential-phase cells of Bacillus licheniformis was studied. The cells were very gently lysed by a combined treatment with lysozyme and Brij 58 in 10 mM. Tris-buffer, pH 7.6, with 60 mM K+, 10 mM Mg2+, 0.5 mM spermine and 0.75 mM spermidine. The proportion of the ribosomal material present in the membrane fraction was estimated after solubilization of the membranes by the combined action of Brij 58, deoxyribonuclease and lipase. 2. Under these conditions of lysis 96% of the total ribosomal material, consisting of subunits (12%) monosomes (20%) and polyribosomes (68%) and most of the cellular DNA, is found to be membrane-bound. 3. In the soluble fraction, containing only 4% of the total cellular amount of the ribosomal material, only subunits and 70S particles and no polyribosomes are found. 4. DNA does not seem to be involved in the binding of the ribosomal material to the membranes. 5. The results will be discussed considering the question of whether the distribution described in this paper represents the true distribution in vivo of ribosomes. [ABSTRACT FROM AUTHOR]

The gycine-rich, arginine-rich histone from calf thymus contains 102 residues of amino acids, distributed as follows: Asp5, Thr7, Ser2, Glu6, Pro1, Gly17,. Ala7, Val9, Met1, Ile6, Leu8, Tyr4, Phe2, Lys10, Lys(Me)1, His2, Arg14. From a tryptic hydrolysate of Gly- and Arg-rich histone, 18 peptides were isolated by fractionation on a column of Chromobeads P followed by purification by paper electrophoresis and chromatography. The amino acid compositions of these peptides are reported. The sequence of 12 of these tryptic peptides has been established. The amino-terminal tryptic peptide is Ac-Ser-Gly-Arg. The carboxylterminal tryptic peptide is Thr-Leu-Tyr-Gly-Phe-Gly-GlyCOOH. [ABSTRACT FROM AUTHOR]

Amino acid analyses of L-lactate dehydrogenase from baker's show that the minimum molecular weight (53 000 daltons) of the protein is much lower than found in the literature (80 000). This result, combined with those reported in the following papers, leads to a revision of the dimeric model generally accepted for cytochrome b2 [ABSTRACT FROM AUTHOR]

The complete sequence (153 amino acids) of horse heart myoglobin has been established. The sequence of a peptide isolated from chymotrypsin hydrolyzates of globin allowed to fill a gap in the tentative sequence previously proposed; this peptide was studied by means of pepsin hydrolysis, action of N-bromosuccinimide on histidyl bonds, and Edman degradation method associated with dansylation. After hydrolysis of globin by chymotrypsin treated by TLCK, the same major peptides were found as after hydrolysis by non-treated chymotrypsin. These peptides were identified by ionexchange resins and bidimensional paper chromatography, and also by the determination of their amino-acid composition. The suppression of secondary cuts explains the presence of new peptides, whose the composition and N-terminal Sequences were determined, it was then possible to confirm several sequences which could be previously deduced from the study of split products after cyanogen bromide treatment. The specificity of chymotrypsin towards certain types of peptide bonds is discussed. Horse myoglobin, as compared with sperm whale myoglobin, contains 18 differences: 17 substitutions and one inversion. The major part of the substitutions are located ih N- and C-terminal sequences: they are all punctiform, resulting from the replacement of only one base in each codon. [ABSTRACT FROM AUTHOR]

This paper deals with investigations in isolated perfused rat livers on tryptophan-oxygenase a under various experimental conditions. Enzyme-activity Showed a linear rise with amounts of tryptophan (0; 125 and 250 mg of tryptophan/kg) in the perfusate. Adrenalectomized and sham-operated animals have been compared and activity in the adrenalectomized rats were significantly lower in all cases. A significant decrease in the substrate induced increase of tryptophan-oxygenase-activity occured 12 h after adrenaleetomy. Substrate-concentration was 250 mg/kg in these experiments. The influence of substrate and cortisol on tryptophan-oxygenase-activity has been investigated 7 days after operation, Combined application of both substrate and steroid resulted in no difference to sham-operated animals when compared to substrate only in the same concentration. On the other hand, in livers from adrenlectomized rats values were significantly higher with combined application than in livers of adrenalectomized animals which received substrate only. The substrate-dependent rise in trsyptophan-oxygenase-activity could not be influenced by actinomycin D in contrast to to he cortisol effect which was significantly inhibited under these conditions. Both "inducers" were inhibited by cycloheximid. These inhibition-experiments suggest and confirm two different mechanisms of the substrate-activation and steroid-induction of tryptophan-oxygenase. [ABSTRACT FROM AUTHOR]

From the lipopolysaccharide of the gram-negative bacterium Rhodopseudomonas capsulata (Athiorhodaceae) a lipophilic sugar was isolated by chromatographic procedures and characterized by mass spectrometry as belonging to the group of 3-O-methyl-6-deoxy-hexoses. Demethylation showed that the parental sugar had the same properties in borate electrophoresis as rhamnose. Comparison with an authentic sample of 3-O-methyl-rhamnose in gas liquid chromatography, paper chromatography and borate electrophoresis showed that the sugar under examination is 3-O-methylrhamnose (acofriose). Investigation of its optical rotation indicates that the sugar has the L-configuration. L-Acofriose (3-O-methyl-L-rhamnose) has not hitherto been found in lipopolysaccharides of gram-negative bacteria. [ABSTRACT FROM AUTHOR]