Premium
Poly( L ‐lysyl‐ L ‐alanyl‐α‐ L ‐glutamic acid)
Author(s) -
Goren H. Joseph,
Fletcher T.,
Epand R. M.
Publication year - 1977
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1977.360160711
Subject(s) - chemistry , hydrolysate , sephadex , monomer , chromatography , column chromatography , dimethylformamide , polymer chemistry , polymer , intrinsic viscosity , amino acid , hydrolysis , organic chemistry , enzyme , biochemistry , solvent
Poly(Lys(Cbz)‐Ala‐Glu(OBzl)) was prepared by the self‐condensation of Lys(Cbz)‐Ala‐Glu(OBzl)‐ONSu in dimethylformamide. After deprotection of the side chains, the product was subjected to Sephadex G‐50 chromatography. The molecular weight of unfractionated and fractionated poly(Lys‐Ala‐Glu) was calculated from a calibrated Sephadex G‐50 column, spectrophotometrically from Dnp‐(Lys‐Ala‐Glu), equilibrium centrifugation, and viscosity measurements. Approximately 21% of the unfractionated material was polymeric with the remaining 79% being cyclic and monomeric material. Treatment of polymer hydrolysate with L ‐amino acid and D ‐amino acid oxidase indicated poly(Lys‐Ala‐Glu) to be optically pure. The apparent pKa's of the two ionizable groups were 4.1 and 9.7.