## Abstract The solution characterization of poly(Lys‐Ala‐Glu) is described. This polytripeptide is zwitterionic at neutral pH and is shown to take on a conformation which is dictated by the state of ionization, molecular weight, temperature, and solvent. The polypeptide is almost entirely α‐helica
Poly(L-lysyl-L-alanyl-α-L-glutamic acid)
✍ Scribed by H. Joseph Goren; T. Fletcher; R. M. Epand
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1977
- Tongue
- English
- Weight
- 651 KB
- Volume
- 16
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
Abstract
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.
📜 SIMILAR VOLUMES
## Abstract Poly(His‐Ala‐Glu) and poly(Lys‐Ala‐Glu) were examined by viscosity and potentiometric titration. These measurements were interpreted in terms of the hydrodynamic size of the above sequential polypeptides. Effects of polymer, size and concentration, and solution‐salt concentration were d
## Abstract Poly(L‐histidyl‐L‐alanyl‐α‐L‐glutamic acid) has been prepared in order to test the acid–base catalytic ability of a carboxyl‐imidazole hydrogen‐bonded system. Two different blocked histidyl‐alanyl‐glutamic acid monomers were used in the polymerization step. The imidazole ring was blocke
## Abstract The hydrolysis of __p__‐nitrophenyl acetate is catalyzed by imidazole, free in solution or as the side chain in poly(His‐Ala‐Glu). This is based on the observations that the reaction is first order in ester and first order in nonprotonated imidazole. Catalysis of __p__‐nitrophenyl aceta
## Abstract The conformation and conformational transitions of poly(His‐Ala‐Glu) have been investigated by ir, nmr, and CD measurements. The results obtained—as well as the results of our previous investigations by potentiometric titration and hydrodynamic techniques [Goren et al., __Biopolymers__
## Abstract Model peptides containing one aromatic residue were synthesized and characterized in order to investigate their interactions with polynucleotides. Chromatographically pure block oligopeptides (L‐alysyl)~__m__~‐(L‐alanyl)~__n__~‐ L‐tyrosyl‐ (L‐alanyl)~__n__~, with __n__ = 3 and __m__=3 o