Structure of branched poly-α-amino acids in dimethylformamide. I. Light scattering

✍ Scribed by N. Eliezer; A. Silberberg

• Publisher: Wiley (John Wiley & Sons)
• Year: 1967
• Tongue: English
• Weight: 469 KB
• Volume: 5
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.1967.360050110

✦ Synopsis

Light scattering of rriulticliain poly-a-amino acids was studied in ditiietliylforInaniiclt: (DMF). The polymers consisted of a backbone of poly-rTlysine of degree of polymerization n with side chains of benzyl Gglutamate and benzyl Gaspartate of degree of polymerization, m, on each +amino gronp. 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. I n 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.