For physiological investigations on the transfer of met,abolites in the pregnant organism it was necessary to prepare a number of natural amino acids with a specific tritium label. The present report relates to the introduction of tritium into the a-position of the basic amino acids, histidine, argi
Synthesis of tritiated poly-L-lysine (γ, δ-T2)
✍ Scribed by M. Fridkin; M. Sokolovsky; E. Katchalski
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1964
- Tongue
- English
- Weight
- 437 KB
- Volume
- 2
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
Tritiated poly-L-lysine (y,&T*) (IX) waa prepared according to the following procedure: Tritiated DL-lysine (y,&T*) (111) was derived from acetarnino-(4amino-A*-buteny1)-diethylmalonate (I) by tritiation followed by acid hydrolysis. The racemic tritiated lysine was converted to its e,N-trifluoroacetyl derivative IV, and the latter resolved via its chloroacetyl derivative by means of hog kidney acylase. The optically active tritiated e,N-trifluoroacetyl-L-lysine (VI) was converted into the corresponding N-carboxyanhydride VII with phosgene, and polymerization carried out in dioxane using triethylamine as initiator. The required tritiated poly-L-lysine (IX, n = 250) was obtained from the blocked polymer VIII after removal of the protecting groups with piperidine. The tritiated polypeptide possessed an activity of 250 mC. per mmole lysine residue. The procedure described enables, however, the preparation of poly-I.-lysine with up to 25 times higher specific activity.
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