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Negative thermal expansibility change for dissociation of lysozyme variant amyloid protofibril
Author(s) -
Ishiguro Ryo,
Matsuo Hiroshi,
Kameyama Keiichi,
Tachibana Hideki,
Fujisawa Tetsuro
Publication year - 2015
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201400468
Subject(s) - lysozyme , dissociation (chemistry) , monomer , chemistry , amyloid fibril , hydrostatic pressure , crystallography , fibril , biophysics , amyloid β , biochemistry , thermodynamics , organic chemistry , physics , disease , pathology , polymer , medicine , biology
A disulfide‐deficient variant of hen lysozyme, 0SS, is known to form an amyloid protofibril spontaneously, and to dissociate into monomers at high hydrostatic pressure. We carried out native PAGE at various temperatures (20–35°C) and pressures (0.1–200 MPa), to characterize the dissociation equilibrium of disulfide‐deficient variant of hen lysozyme amyloid protofibril. Based on the density profiles, the partial molar volume and thermal expansibility changes for dissociation, Δ v D and Δ e D , were obtained to be −74 cm 3 /mol at 25°C and −2.3 cm 3 mol −1 K −1 , respectively. The dissociation of amyloid fibril destroys the cross β‐structure, and such conformational destruction in native protein fold rarely accompanies negative thermal expansibility change. We discussed the negative thermal expansibility change in terms of hydration and structural packing of the amyloid protofibril.