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ID 34798
file
creator
Mimura, Shigefumi
Yamato, Takahisa
Kamiyama, Tadashi
Gekko, Kunihiko
subject
Isothermal compressibility
Lysozyme
Molecular evolution
Nonneutral pathway
Normal-mode analysis
Volume fluctuation
NDC
Biology
abstract
The evolution of structural fluctuations of proteins was examined by calculating the isothermal compressibility (beta(T)) values of chicken lysozyme and its six evolutionary mutants at Thr40, Ile55, and Ser91 (a ternary mutant corresponding to bobwhite lysozyme) from their X-ray structures by normal-mode analysis at 300 K. The Or values of the two extant lysozymes from chicken and bobwhite were 1.61 and 1.59 Mbar(-1), respectively, but five other evolutionary mutants showed larger beta(T) values of up to 2.17 Mbar(-1). These results suggest that ancestral lysozymes exhibit larger volume fluctuations than extant ones, and hence that the molecular evolution of lysozymes has followed a nonneutral evolutionary pathway. The evolutionary mutants contained large amount of cavities, although no change was visible in the X-ray structures. There was a linear correlation between beta(T) and total cavity volume, predicting that the cavity volume or atomic packing is an important factor regulating volume fluctuations during the molecular evolution of this protein. (C) 2011 Elsevier B.V. All rights reserved.
journal title
Biophysical Chemistry
volume
Volume 161
start page
39
end page
45
date of issued
2012
publisher
Elsevier Science BV
issn
0301-4622
ncid
publisher doi
language
eng
nii type
Journal Article
HU type
Journal Articles
DCMI type
text
format
application/pdf
text version
author
rights
(c) 2012 Elsevier B.V. All rights reserved.
relation url
department
Ohters