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Structure of branched poly‐α‐amino acids in dimethylformamide. I. Light scattering
Author(s) -
Eliezer N.,
Silberberg A.
Publication year - 1967
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.1967.360050110
Subject(s) - chemistry , polymer , polymerization , degree of polymerization , molecule , solvent , polymer chemistry , dimethylformamide , amino acid , light scattering , static light scattering , scattering , crystallography , organic chemistry , biochemistry , physics , optics
Light scattering of multichain poly‐α‐amino acids was studied in dimethylformamide (DMF). The polymers consisted of a backbone of poly‐ L ‐lysine of degree of polymerization n with side chains of benzyl L ‐glutamate and benzyl L ‐aspartate of degree of polymerization, m , on each ε‐amino group. The backbone length n is known and m is obtained by amino acid analysis. The results on a series of such materials confirm this structure and show that the molecules are dissolved in highly compacted conformations. It was found that DMF is a poor solvent for these polymers. In the case of the higher molecular weight polymers, the solutions initially were not molecularly disperse. The aggregates were resistant to dilution in the experimental range. Mild heat treatment, however, disaggregated the solutions irreversibly, and the light‐scattering data indicated that a structural rearrangement of the molecules had occurred.