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Conformational behavior of poly-N5-(3-hydroxypropyl)-L-glutamine in water–methanol mixtures studied by 13C nmr and CD spectroscopy

✍ Scribed by R. Di Blasi; A. S. Verdini


Publisher
Wiley (John Wiley & Sons)
Year
1974
Tongue
English
Weight
733 KB
Volume
13
Category
Article
ISSN
0006-3525

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✦ Synopsis


Abstract

The helix–coil transition of poly‐N^5^‐(3‐hydroxypropyl)‐L‐glutamine (PHPLG) has been studied in methanol–water by CD and cmr spectroscopy. For polydisperse PHPLG, two separate peaks arising from residues in helical and random‐coil conformations are observed during the transition for both main‐chain carbons. These results are discussed and compared to those observed in the case of a polymer sample obtained by racemization of PHPLG in 0.1 M NaOH and of PHPLG samples of controlled molecular weight and dispersity. The dominant influence of the molecular‐weight heterogeneity on the double‐peak phenomenon has been verified. The linewidths and chemical shift of the ^13^C resonances are discussed in terms of side‐chain–main‐chain interactions and side‐chain solvation.