Premium
Conformational Properties of Histidine Related Polymers
Author(s) -
Scoffone E.,
Peggion E.
Publication year - 1974
Publication title -
israel journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.908
H-Index - 54
eISSN - 1869-5868
pISSN - 0021-2148
DOI - 10.1002/ijch.197400012
Subject(s) - chemistry , histidine , polymer , chromophore , deprotonation , molecule , side chain , crystallography , polymer chemistry , computational chemistry , organic chemistry , ion , enzyme
In briefly reviewing the results of conformational studies on histidine‐related polymers, two main problems appear to be unsolved at the present time, namely, the conformations to be assigned to poly‐(1‐benzyl)‐L‐histidine · HClO 4 in trifluoroethanol and to charge‐free poly‐L‐histidine (PLH) in water. In both cases the right‐handed α‐helical form must be ruled out. The optical rotatory properties are of little help in solving the problem unambiguosly, because of the complication of the side‐chain chromophores. By slow neutralization of PLH hydrochloride solutions, solid samples could be obtained in which the polymer molecules should have the same conformation as in solution. Similarly, slow addition of HClO 4 to a concentrated solution of poly‐(1‐benzyl)‐L‐histidine (PBLH) causes precipitation of PBLH · HClO 4 in which the same conformation as in solution should be maintained. X‐ray diffraction studies on polymer samples obtained in such a way should provide more information for the conformation of PBLH · HClO 4 and of deprotonated PLH in water.