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Microwave dielectric study on bound water of globule proteins in aqueous solution
Author(s) -
Miura Nobuhiro,
Asaka Nobuyuki,
Shinyashiki Naoki,
Mashimo Satoru
Publication year - 1994
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.360340307
Subject(s) - chemistry , aqueous solution , bound water , relaxation (psychology) , dielectric , molecule , rotational correlation time , crystallography , analytical chemistry (journal) , chromatography , organic chemistry , psychology , social psychology , physics , optoelectronics
Abstract A dielectric relaxation peak due to bound water of globule proteins in aqueous solution was observed at first by the use of a time domain reflectometry. This peak locates around 100 MHz as well as that of the aqueous DNA solution and the moist collagen, and has a relaxation strength in proportion to surface of the globule protein except for trypsin and pepsin of hydrolase. It is suggested that this peak is caused by orientation of bound water molecules on the protein surface. The number of bound water molecules estimated is in good agreement with that obtained by other method such as x‐ray analysis. The solution exhibits another peak below 100 MHz, which is caused by the rotation of globule protein supplemented by migration of the counterion. Its relaxation time is completely proportional to the molecular weight of the protein. © 1994 John Wiley & Sons, Inc.