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A circular dichroism study of valinomycin barium ion complex
Author(s) -
Devarajan S.,
Easwaran K. R. K.
Publication year - 1981
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.1981.360200504
Subject(s) - valinomycin , chemistry , circular dichroism , salt (chemistry) , hydrogen bond , crystallography , ion , perchlorate , isopropyl , inorganic chemistry , stereochemistry , molecule , organic chemistry
Complex formation of valinomycin with Ba 2+ ions was investigated by circular dichroism spectroscopy. The results indicated that Ba 2+ forms entirely different types of complexes when compared with K + . The data with perchlorate salt showed evidence for the formation of less stable V 2 C (peptide sandwich), VC (1:1), and VC 2 (ion sandwich) complexes followed by a stable final complex upon gradual addition of salt (V stands for valinomycin and C for the cation). This final complex possibly has a flat structure with no internal hydrogen bonds, similar to that of valinomycin in highly polar solvents. The possible complexation mechanism and the role played by anions and isopropyl side chains are highlighted.