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Lysine succinylation of proteins has potential impacts on protein structure and function, which occurs on post-translation level. However, the information about the succinylation of proteins in tea plants is limited. In the present study, the significant signal of succinylation in tea plants was found by western blot. Subsequently, we performed a qualitative analysis to globally identify the lysine succinylation of proteins using high accuracy nano LC-MS/MS combined with affinity purification. As a result, a total of 142 lysine succinylation sites were identified on 86 proteins in tea leaves. The identified succinylated proteins were involved in various biological processes and a large proportion of the succinylation sites were presented on proteins in the primary metabolism, including glyoxylate and dicarboxylate metabolism, TCA cycle and glycine, serine and threonine metabolism. Moreover, 10 new succinylation sites were detected on histones in tea leaves. The results suggest that succinylated proteins in tea plants might play critical regulatory roles in biological processes, especially in the primary metabolism. This study not only comprehensively analyzed the lysine succinylome in tea plants, but also provided valuable information for further investigating the functions of lysine succinylation in tea plants.

Proteins with homo-repeats of more than 4 amino acid residues in length were examined to understand whether some splicing sites in pre-mRNA may be attributed to homo-repeats in human proteins. The human proteome was found to contain a total of 404 proteins with homo-repeats that account for at least one splicing site in pre-mRNA. Pre-mRNA splicing sites were more often found in the C-terminal part (67%) than in the middle orN-terminal part of a homo-repeat. Ten homo-repeats were identified to have two splicing sites per repeat. The repeats were lysine homo-repeats in all but one case.

Oligopeptides present in the living cell were found to have antioxidative activity and to be involved in the regulation of antioxidant balance by interaction with the redox-dependent cellular signaling cascades. Experiments on animal models have shown that the introduction of oligopeptides causes geroprotective and adaptogenic effects. In the present work, we investigate the biological action of a number of synthetic oligopeptides using bacterial biosensors. This approach allows us to precisely estimate the antioxidant properties of the compounds without affecting their participation in regulatory cascades typical to eukaryotic cells. It has been shown that the ability of oligopeptides to protect cells from action of physical prooxidant factors (UV irradiation) is related to the presence of a lysine residue in the molecule. For chemical pro-oxidants (dioxidine), we have observed a similar, though less strict pattern. This effect also correlates with DNA-protective activity of the investigated oligopeptides.

Histone H3 posttranslational modifications play important role in chromatin remodeling and are involved in gene expression regulation during long term memory formation. If acetylation and phosphorylation of histones has been intensively studied for several years, the role of methylation during learning is only under establishment. Histone methylation is an interesting subject, since it can both activate and repress gene expression. By using food avoidance behavior of mollusk Helix as a model, we analyzed lysine 4 histone H3 tri-methylation (H3K4) and lysine 9 H3 di-methylation (H3K9), which induces and represses genes correspondingly. We showed that there was a significant increase in histone H3 methylation at lysine 4 and lysine 9 in Helix central nervous system upon consolidation of long term memory. Data obtained show the involvement of histone methylation to the epigenetic mechanisms of long-term memory formation in mollusk Helix on transcription repression and activation levels. Beside this, induction ofH3 methylation at lysine 9 can reflect influence of inhibitory processes, playing an important role in central nervous system functioning.

This article reviews one of the most important post-translational protein modifiers--ubiquitin. The basic mechanisms of conjugation reactions of ubiquitin with substrate, factors influencing the ubiquitination and its role in regulation of different cellular processes have been considered.

The function of lysine-binding sites in kringle domains K1-4 and K5 of plasminogen (Pg) during its activation by streptokinase (SK) was studied. Activation rates of Glu- and Lys-Pg exceed activation rate of mini- and micro-Pg 26 and 40 times, respectively. 6-Animohexanoic acid (6-AHA) in concentrations from 10(-5) to 10(-2) M inhibits activation of Glu-, Lys- and mini-Pg and does not impact the activation of micro-Pg. Complete inhibition of Lys-Pg activation occurs with presence of 10(-3) M 6-AHA while 90% inhibition of mini-Pg activation and 70% inhibition of Glu-Pg activation occur with 10(-2) M 6-AHA. Isolated kringles K1-3 and K4 of Pg inhibit activation of Glu-Pg by SK and concentrations [I]50 are 4.0 and 8.1 x 10(-6) M, respectively. Catalytic activity of Glu-Pg-SK, Lys-Pg-SK and Pm-SK complexes with respect to S 2251 is not inhibited by 6-AHA in concentrations from 10(-5) to 10(-2) M. Activation of substrate Pg by Pm-SK complex is also inhibited by 6-AHA in concentrations from 10(-5) to 10(-2) M; however, this effect of inhibition is significantly weaker than that with activation by SK. Cleavage of C-terminal Lys or chemical modification of NH2-groups of amino acid residues in SK molecule also results in the decrease of the Glu-Pg activation rate. Lysin-binding sites in K1-4 and K5 of Pg molecule are important at different steps of Pg activation process which includes formation of equimolar complex; structural reorganizations resulted in formation of active center in Pg; and binding of substrate Pg with Pg-SK complex. Lysin-binding sites in K1-4 of Pg are necessary for maintenance of high rate of Pg activation by SK.

The histochemical method developed by the author was used to localize lysine- and arginine-rich proteins in the rat, rabbit, feline, canine, and human brains. A great difference was found between neurons (enlarged in lysine-rich proteins) and neuroglia (abundant in arginine-rich proteins). It was suggested that arginine-rich neuroglia might be responsible for or involved in supplying the brain with L-arginine, a precursor of nitric oxide (NO), a secondary messenger that is likely to be used by ancient type neurons. A direct relationship was established between the complexity of the brain structural and functional organization and the increases in lysine-rich neuronal proteins. This assumes that, by analogy with L-arginine synthesis of NO, L-lysine can be a precursor of a hypothetical messenger used by neurons of the higher brain regions. Responses of neurons to experimental exposures were assessed by the changes occurring in the levels of protein and its synthesis. Responses of neurons in the cortex and subcortical areas of the brain were shown to be non-specific and characterized by automatism, but to have specific features in different types of neurons.

A series of RNA-hydrolyzing constructions was synthesized on the basis of peptide-like molecules containing residues of L-lysine, histamine and histidine methyl ester. These were shown to hydrolyze RNA effectively at neutral pH values. The in vitro transcript of tRNA(Lys) from human mitochondria and a tRNA-like fragment of RNA of Turnip Yellow Mosaic Virus were used in the experiments. Our chemical RNases quantitatively depolymerize some definite sequences (CA > or = UA > CG >> UC, CC, or CU) in both RNA molecules under optimum conditions. Moreover, no other sites were affected and no statistical hydrolysis was observed even after prolonged RNA incubation with the compounds of this series. The depolymerization rate of the RNA substrates exhibits a complex dependence on the concentration of ions of monovalent metals and on the concentration of the artificial ribonucleases.

The effect of field drought on gene expression in developing Zea mays L. grain and the influence of the imbalance of essential amino acids on the expression of genes in white-rat liver at the mRNA stability level were studied. A special ommp system, which included incubation (65 degrees C, 5 min) of an aqueous preparation of highly purified, high molecular-weight RNA isolated in the presence of Mg2+, was used for the analysis of mRNAs relative stability in eukaryotes. Drought changed the relative stability of seven specific mRNA in the maize developing grain: there occurred a considerable stabilization of the eEF-1 alpha mRNA and, conversely, a destabilization of the 19-kDa zein mRNA. The imbalance for lysine and tryptophan reduced the stability of the total polyadenylated mRNA and the eEF-1 alpha mRNA of rat liver. The mRNA stability positively correlated with animal growth. Thus, using the ommp system, the effect of stressful factors on the stability of specific mRNA in eukaryotes--depending on mRNA species, stressful factors, and the tissue--was shown.

Activities of basic carboxypeptidases (CP) in rat brain regions and peripheral tissues were determined on postnatal days 0-90. The highest phenylmethylsulfonyl fluoride-inhibited activity was detected immediately after birth; activity decreases on day 10 with subsequent increase on day 20 and decrease on day 90. The CPE activity was the lowest immediately after birth, increased on day 30, and decreased on day 90. The lysosomal CPB activity was highest at birth and on day 90 and was the lowest on day 20. The activity of CPN slowly increases till day 20 and then it decreases. The relationship between dynamics of basic CP activity in ontogenesis and functional role of these enzymes is discussed.

The effects of trinitrophenylation of lysyl residues of rabbit skeletal myosin subfragment 1 (S1) on thermal denaturation of S1 in the absence of nucleotides, in the presence of ADP and within S1 complexes with ADP and Pi analogues, orthovanadate (Vi) or beryllium fluoride (BeFx), have been studied by differential scanning calorimetry. It has been shown that lysyl trinitrophenylation significantly affects the thermal stability of S1, changes its domain structure, promotes the decomposition of S1.ADP.Vi and S1.ADP.BeFx complexes, and strongly prevents the structural changes in the S1 molecule induced by the formation of the S1.ADP.Vi complex without any effect on the thermal stability of S1 within S1.ADP and S1.ADP.BeFx complexes. It has been demonstrated that the effects of trinitrophenylation on the S1 structure are mainly due to specific modification of the epsilon-amino group of the Lys-83 residue.

We have identified the lac repressor amino acids which form cross-links with partially depurinated DNA and hence are proximate to it. Only lysine-33 is cross-linkable in specific complex with lac operator. At the presence of inducer molecules lysine-33 remains cross-linkable. However, the N-terminal alpha-aminogroup was additionally cross-linked with the boundaries of lac operator. We conclude that orientation of the DNA-binding domain of the repressor is reversed by inducer binding.

The sources of production of aminoacyl oxidases, their principal biochemical properties have been considered. The role of lysine oxidase in the mechanism of DNA, RNA inhibition in some forms of the tumor cells in vivo has been discussed. The prospects of the enzyme use in the analytical practice and medicine are presented.

Catalytic activity of destabilase has been studied in hydrolyses of synthetic and natural substrates. High specificity of the enzyme is shown in hydrolysis of endo-epsilon-(gamma-Glu)Lys isopeptide bonds.

The effect of L-lysine on some reactions catalysed by plasmin and the plasmin-streptokinase activator complex has been studied. The constants for competitive inhibition by L-lysine of the benzyloxycarbonyl-L-lysine p-nitrophenyl ester hydrolysis by the activator (Ki 116 mM), of the plasminogen activation by the activator (Ki 8 mM) and of fibrinolysis by plasmin (Ki 3 mM) were determined. It was found that L-lysine at concentrations below 0.05 M, which do not affect the activator's esterase activity, does inhibit fibrinolysis by plasmin and the activator complex. The effect of L-lysine on fibrinolysis under the action of the activator is complex: it inhibits both the activation of clot-entrapped plasminogen by the activator and lysis of fibrin by the plasmin formed. This inhibitory action of L-lysine is largely related to the fact that it lowers the sorption of the activator, plasminogen and plasmin on fibrin, competing with fibrin for their lysine-binding sites as well as worsens the activator-plasminogen binding.

It has been shown that during novocaine (4.6 x 10(-3) M) induced formation of the segregation apparatus (SA) the total protein synthesis decreases, the synthesis of certain proteins being characterized by a high rate turnover. In the intact erythrocytes, 1 x 10(-2) cycloheximide (CHM) inhibits the novocaine induced formation of segregation apparatus (SA) and protein synthesis by 90%. The combined action of novocaine and CHM on erythrocytes is accompanied by a decrease in CHM inhibiting effect on protein synthesis. This effect retains for 1.5 h during the action of both compounds. Some vacuoles of SA disposed cytochemically exposed acid phosphatase (AP), which enabled us to consider these as lysosomes. According to AP distribution in lysosomes, they can be classified into 3 groups. In group 1 AP is distributed along the membrane of vacuoles, in group 2 it is associated with the material inside the lysosome, and in group 3 the enzyme is both distributed along the membrane and associated with the material enclosed within the segregation vacuole. Such a mode of AP distribution reflects presumably the functional heterogeneity of lysosomes.

Lys-172 residue of bacteriophage T7 RNA polymerase (T7RP) was substituted for Leu and Gly and Lys-172, Arg-173 were deleted by the site-directed mutagenesis using synthetic oligonucleotides. The specific activity of all mutant enzymes did not differ significantly from that of the wild-type (w.t.) T7RP while for Gly-172 mutant (G172) it was somewhat lower. Leu-172 (L172) and deletion (DEL172-3) mutants were able to direct RNA synthesis on the templates lacking the T7 promoter. DEL172-3 was not able to synthesize extraneous RNA sequences in addition to the expected run-off transcripts. L172 and DEL172-3 mutants revealed altered template specificity toward various DNA templates and showed the lower stability of enzyme-promoter complexes. The possible role of Lys-172 likely belonging to an interdomain "stretch" is discussed.

The effect of diet on induction of monooxygenases and distribution of radioactivity from 2-14-C-lysine in fractions of liver homogenate, muscle homogenate and blood of male rats treated with phenobarbital (80 mg/kg, three days) was studied. 2-14-C-lysine was injected intraperitoneally 24 h before the first injection of phenobarbital. It was demonstrated that monooxygenase induction, increase of relative liver weight and incorporation of radioactivity from 2-14-C-lysine into fractions of liver homogenate in phenobarbital-treated rats fed diet deficient in lysine, methionine, threonine and vitamins A, C and E were more pronounced as compared with the similarly treated rats which were fed a balanced diet. The possibility of mobilization of deficient essential components to liver from other organs and tissues for maintenance of monooxygenase induction is discussed.

Chemical modification of lysine residues of eukaryotic tyrosyl-tRNA synthetase was studied. It was shown that only four out of 22 lysine residues per enzyme dimer could be modified with pyridoxal-5'-phosphate. This modification led to the inactivation of tRNATyr aminoacylation by more than 90% but did not practically affect the rate of ATP-[32P]pyrophosphate exchange. Low molecular weight substrates (ATP, ATP-tyrosine) weakly protected the enzyme from inactivation, whereas tRNATyr afforded a much more effective protection. It was supposed that lysine residues of tyrosyl-tRNA synthetase can be involved in the interaction with tRNATyr.

The effect of diet on induction of monooxygenases and distribution of label from 2-14C-lysine in fractions of liver homogenate, muscle homogenate and blood of male rats treated with phenobarbital (80 mg/kg, three days) was studied. 2-14C-lysine was injected intraperitoneally 24 h before the first injection of phenobarbital. It was demonstrated that monoxygenase induction, increase of relative liver weight and incorporation of label from 2-14C-lysine into fractions of liver homogenate in phenobarbital-treated rats were more pronounced as compared with the similarly treated rats that were fed a balanced diet. The possibility of mobilization of deficient essential components to liver from other organs and tissues for maintenance of monoxygenase induction is discussed.

Affinity of plasminogen fragments K1, K2-3, K4 and K5 for 6-aminophenyl-Sepharose was investigated to characterize the lysine-binding sites of the protein. K1 and K5 fragments were bound to the affinity column, whereas kringle 2-3 and kringle 4 were not. The results obtained and data known from literature have indicate that two types of lysine-binding sites are present in the plasminogen molecule. Both positively and negatively charged groups of the ligand are necessary for binding with the first-type sites (K4 and K2-3). The interaction between ligands and the second-type sites localized in kringles 1 and 5 is provided by their positively charged group only.

The effect of L-lysine HCl concentrations, pH, temperature and cultivation conditions on the synthesis of intracellular lysine decarboxylase (LDC) by Vibrio sp. was studied. The highest LDC activity was observed in a 4-hour culture grown at 30 degrees on a nutrient medium, pH 5.15 containing 0.9% L-lysine HCl as an inducer. Under these conditions the LDC activity of the bacterium was 8.43 U/mg dry cells.

Stimulation of lipid peroxidation /increase in content of conjugated dienes and of malone dialdehyde/, which was prevented by administration of isoniazid or sodium thiosulphate, was detected in mitochondrial fraction of liver tissue obtained from rats with tuberculosis of lungs. At the same time, in the mitochondrial fraction a significant decrease in tyramine and serotonin deamination rates and an increase in histamine, lysine and putrescine deamination rates were observed. The altered ratio of the deamination rates of the nitrogenous compounds may be prevented by administration of isoniazid and sodium thiosulphate into the animals. A hypothesis is discussed on the possible significance of qualitative alteration /transformation/ in catalytic properties of the mitochondrial monoamine oxidase induced by the stimulation of lipid peroxidation as a cause underlying the reversible impairments in ratios of rates of the nitrogenous compounds deamination in tuberculosis.

Experiments on the rat liver homogenates and slices show that formate stimulates carbon incorporation from [1-14C] lysine and [2-14C] acetate into proteins and from [2-14C] acetate into lipids. The stimulating effect depends on both the formate concentration and nature of the labelled precursor. The in vitro experiments demonstrate the highest stimulating effect on the metabolism of both proteins and lipids under administration of 2 microM formate per 100 g of animal mass. Determination of the label incorporation rate at different time after formate administration showed that the latter evokes an intensified synthesis of protein with rate of its decay remaining the same.

It was been shown that in the line of forms of amphibia, reptiles, mammals, including man, the histochemical differentiation of the epidermis is related with changes in protective and transitory zones. For instance, in amphibia the accomodation to the terranian medium is accompanied by establishment of the vertical histochemical gradient in the epidermis which is manifested by accumulation of a protein rich in cationic and sulfhydril groups in the protective zone. The epidermis of reptiles is characterized by presence of high concentrations of a protein rich in cystine in the protective zone. The transient zone is formed on the border of the protective and germinative zones. The epidermis of mammals retains in general features the histochemical type of differentiation of the protective zone which had appeared in reptiles. However, the transient zone of the mammalian epidermis has a high concentration of proteins rich in histidine and arginin. The histochemical differentiation of the human epidermis is related with the distribution of the hairy integument.

Circahoralian rhythm of the intensity of 3H-lysine incorporation into proteins of the retina ganglionic cells and of the protein synthesis rate in the isolated retina with an amplitude of fluctuations of 35-36% of the mean has been found in active adult susliks. During hibernation, no circahoralian fluctuations of protein metabolism were recorded. Circahoralian rhythms of protein metabolism can serve as a marker of the tissue functional activity.

The interaction between diamine oxidase (DAO) of human placenta and carboxyl-substituted lysines, including N-terminal lysine containing peptides, occurs at rather a high rate and is characterized by the following features. First, the enzyme catalyzes the oxidative deamination of one amino group in the N-terminal lysine at a rate which is inversely proportional to the peptide length. Second, the bound derivatives induce a noncompetitive reversible inhibition of DAO which is enhanced during their coincubation. The inhibiting capacity of this compound is directly proportional to the peptide length; therefore, the tripeptides with the N-terminal lysine can be effective inhibitors that are not practically deaminated in the presence of DAO. Third, the binding of carboxyl-substituted lysines to DAO as well as the inhibition reaction are reversible processes and, with some limitations, can be used for enzyme purification. An analysis of the total activity of DAO in the placenta before and after fractionation of tissue extracts on molecular sieves showed that part of the enzyme is in a blocked state in vivo which does not exclude the possibility that N-terminal lysine containing peptides are related to natural DAO inhibitors.

The incorporation of (14C) lysine (to characterize the biosynthesis of cellular proteins) and (14C) glycine (for silk fibroin) in free and membrane-bound polyribosomes was studied in fibroin portion of the silk gland of Bombyx mori silkworm in the V instar. It was shown that although the membrane-bound polyribosomes are found in posterior silk gland from the beginning of the V instar, the fibroin biosynthesis in the membranebound polyribosomes takes place predominantly in the second part of the V instar. On the other hand the cellular proteins are synthesized mostly in the free polyribosomes in the first half of the V instar. In the second half of the V instar in the sucrose gradient zone corresponding to free polyribosomes, monoribosomes unable to synthesize protein for the absence of mRNA are present. Nevertheless, these ribosomes isolated from the fibroin part of the silk gland in the end of the V instar do synthesize polyphenylalanine in the presence of poly (U), and aminoacyl-t-RNA-synthetases and tRNA's obtained from the posterior silk gland.

Inactivation of inorganic pyrophosphatase from E. coli by pyridoxal-5'-phosphate is due to the modification of a lysine residue located in the tryptic peptide with the Asp-Leu-Pro-Glu N-terminal sequence. In course of the enzymatic process this lysine-residue appears to be in the protonated state and either operators as the proton donor for the product of the enzymatic reaction or is involved in stabilization of the transition state.

The time-course of changes in casein and gluten utilization was elucidated in rats in 2 experiments lasting 52 and 84 days by means of determining the protein effectiveness coefficient (PEC). The PEC was measured every other 4 days. Casein utilization decreased continuously and almost rectilinearly, whereas gluten utilization first rose (adaptation) and then descended (deadaptation). It is concluded that the time-course of changes in utilization of unbalanced wheat protein is linked not only with restitution of the enzymatic systems but also with mobilization and depletion of the reserve possibilities of the body.

"In vitro" incubated slices of the rat liver, by the method of interferometry combined with radioautography, have demonstrated hour's rhythmic fluctuations in protein concentration and 3H-lysine incorporation into proteins. The biochemical method has demonstrated fluctuations in protein synthesis rate in the same cells with an average period of about one hour. The possibility to apply the interferometric method in combination with radioautography for revealing quantitative changes of protein in slices of organic cultures is demonstrated.

Chemical modification of cytochrome P-450scc by lysine-specific reagents has been performed. Modification of the hemoprotein was shown to result in the loss of its ability to interact with adrenodoxin. With a view of identifying lysine residues involved in the interaction with adrenodoxin, cytochrome P-450scc was modified by succinic anhydride in the presence of adrenodoxin. After the removal of ferredoxin, the modification was performed with the use of a radioactively labeled reagent. Subsequent hydrolysis of the succinic hemoprotein by chymotrypsin and separation of the peptides obtained by high pressure liquid chromatography resulted in the isolation of seven chymotryptic peptides containing labeled lysine residues. These amino acid sequences were identified. The role of lysine residues of cytochrome P-450scc in complex formation with adrenodoxin is discussed.

Protein biosynthesis is studied in red and white rat shank muscles in vitro. It is found that the incorporation rate of 14C-lysine in red muscle was 2-fold higher than that in white muscle. The difference in the lysine incorporation rate into muscle proteins studied increased with the increase of lysine molar concentration in the incubation medium, which was probably due to a selective protein synthesis activation in the red muscle. A higher level of 14C-lysine incorporation in red muscle proteins was found under similar uptake of the labelled amino acid in both red and white muscles. RNA synthesis rate was the same in both muscles and its inhibition with actinomycin D did not affect the ratio of protein synthesis rates in red and white muscles.

Using the method of fibr-DNA autoradiography, 3H-lysine labeled L cells were examined. Fibr-labeled structures as long as 400 mkm were revealed. The pattern of labeling along fibres was same as when cells were labeled with 3H-thymidine. In cross experiments when 3H-lysine and 3H-thymidine were used simultaneously, the pattern of labeling remained the same. The data obtained may evidence that the complexation of new synthesized histones with DNA takes place synchronously with the replication, and in the points of chromosome replication.

The intensity of total protein synthesis was estimated by 3H-lysine incorporation in the hind limb tissues of mesodermal origin in the common frog tadpoles. In the course of limb development and loss of regenerative ability, the intensity of 3H-lysine incorporation in the differentiating muscle tissue and cartilage epiphysis increased; the cartilage diaphysis is characterized by the low level of 3H-lysine incorporation. At the stage Ia of regeneration after the limb amputation the intensity of labeling in the tissues of organ residue descreases until the stage of regeneration blastema formation and then, during the formation of limb rudiment, rapidly increases. The blastema cells are characterized by the high intensity of 3H-lysine incorporation. At the stage IIIa of wound healing after the limb amputation, the intensity of 3H-lysine incorporation in the differentiated muscles and cartilage epiphysis gradually decreases. The intensity of labeling in the scar cells is high enough.