Search

Isoaccepting tRNA's as their mixed trialkylammonium salts have been separated electrophoretically on a normally hydrophobic support membrane. In studies on baker's yeast tRNA, the two known major Met-tRNA's have been well separated from one another and from what may be a minor Met-tRNA. An electrophoretic study of two major Met-tRNA species after their separation by reversed-phase partition chromatography indicates that the less lipophilic of the two species has the higher electrophoretic mobility. One major and four minor radioactive loci have been found on the electrophorograms of baker's yeast tRNA which had been charged with [ 14 C]phenylalanine. The nature of the Phe-tRNA's which occupy the minor loci remains to be determined. It is suggested that they may include undermethylated precursor forms of the main Phe-tRNA species of baker's yeast.

Using a chromatographic technique, the adsorption of the polyribonucleotides s-RNA and poly-A provided with tri-n-butylammonium ions from an aqueous solution on to the surface of polymeric hydrocarbon granules has been demonstrated. The aqueous solution from which adsorption takes place is the aqueous phase which results on agitating together n-butanol (100), water (130), tri-n-butylamine (10), n-butyl ether (10), and glacial acetic acid (2.5) (parts by volume). Microporous polyethylene granules, microporous fluorinated polyethylene granules, and solid grains of polyethylene powder have been employed as adsorbents. The adsorbed polyribonucleotides could be eluted by aqueous solutions of sodium chloride, urea, or triethylammonium acetate. s-RXA with tri-n-butylammonium counterions could also be adsorbed on polymethacrylic acid in tri-n-butylammonium form and eluted therefrom with aqueous urea solutions. It is considered that the adsorption from aqueous solution of polyribonucleotides with tri-n-butylammonium counterions on polymeric hydrocarbon surfaces is mediated by hydrophobic bond formation. Van der Waals forces may also contribute to the bonding. It is suggested that studies on the adsorption of polynucleotides provided with counterions: possessing nonpolar groups at an aqueous solution-polymeric hydrocarbon interlace may permit the elaboration of experimental systems to serve as models for the evaluation of the role of hydrophobic and van der Waals bonding forces in the interaction of polynucleotides with cell membrane surfaces.

Summary1. A new technique of resolving and identifying the members of the B6 family of growth factors is described. It involves the use of paper partition chromatography coupled with a microbial indicator.2. Using this method it has been demonstrated that pyridoxal undergoes a non-enzymatic transamination reaction even in the cold. Pyridoxal also appears to react reversibly with other amino acids.3. The reaction between cysteine and pyridoxal differs from that with other amino acids in that one can demonstrate the formation of at least one adduct which moves more slowly on the chromatogram than does pyridoxamine. This reaction may produce a new form of vitamin B6 which may also have a transient existence in nature.4. The technique described should prove of value as a means of establishing the purity of the various forms of vitamin BG used, in biological and biochemical studies.5. The general technique employing paper partition chromatography and microbial indicators should be of value in resolving other m...