PEDS Advance Access originally published online on May 23, 2006
Protein Engineering Design and Selection 2006 19(8):355-358; doi:10.1093/protein/gzl019
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The correlation between protein stability and dipole moment: a critical test
Laboratorium für Biochemie und Bayreuther Zentrum für Molekulare Biowissenschaften, Universität Bayreuth D-95440 Bayreuth, Germany
1To whom correspondence should be addressed. E-mail: fx.schmid{at}uni-bayreuth.de
Improving the stability of proteins is a major aim in basic and applied protein science. Querol and coworkers calculated changes in the quasi-electric dipole moment of a protein and used it as a simple criterion to predict stabilizing charge mutations. They employed this method to propose for the bacterial cold shock protein Bc-Csp a number of charge mutations that should have a strong influence on stability. We produced eight variants of Bc-Csp with such mutations and measured their stabilities experimentally. However, we could not find a correlation between the stability and the quasi dipole moment of these variants. Possibly, the quasi dipole moment reflects only a secondary aspect of the changes that are caused by charge mutations in a protein.
Keywords: cold shock protein/electric dipole moment/electrostatic interactions/protein stabilization
Received March 13, 2006; revised April 7, 2006; accepted April 12, 2006.