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PubMed · 3477797

Enhanced protein thermostability from site-directed mutations that decrease the entropy of unfolding.

B W Matthews·H Nicholson·W J Becktel
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Abstract

It is proposed that the stability of a protein can be increased by selected amino acid substitutions that decrease the configurational entropy of unfolding. Two such substitutions, one of the form Xaa----Pro and the other of the form Gly----Xaa, were constructed in bacteriophage T4 lysozyme at sites consistent with the known three-dimensional structure. Both substitutions stabilize the protein toward reversible and irreversible thermal denaturation at physiological pH. The substitutions have no effect on enzymatic activity. High-resolution crystallographic analysis of the proline-containing mutant protein (Ala-82----Pro) shows that its three-dimensional structure is essentially identical with the wild-type enzyme. The overall structure of the other mutant enzyme (Gly-77----Ala) is also very similar to wild-type lysozyme, although there are localized conformational adjustments in the vicinity of the altered amino acid. The combination of a number of such amino acid replacements, each of which is expected to contribute approximately 1 kcal/mol (1 cal = 4.184 J) to the free energy of folding, may provide a general strategy for substantial improvement in the stability of a protein.

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CalorimetryDrug StabilityMuramidaseMutationProtein ConformationProteinsT-PhagesThermodynamicsJournal ArticleResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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BibTeXRIS

B W Matthews, H Nicholson, W J Becktel. 1987. Enhanced protein thermostability from site-directed mutations that decrease the entropy of unfolding.. https://doi.org/10.1073/pnas.84.19.6663

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