Linked Life Data

19830687

Source:http://linkedlifedata.com/resource/pubmed/id/19830687

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2009-10-26
pubmed:databankReference
pubmed:abstractText
Enhancing protein conformational stability is an important aspect of protein engineering and biotechnology. However, protein stabilization is difficult to rationalize as it often results from the small cumulative and intertwined effects of multiple mutations. Here, we analyzed the mechanisms behind a remarkable 13 degrees stabilization produced by a single A14G and a double A14GA38V mutation in BPTI-[5,55], a natively folded bovine pancreatic trypsin inhibitor variant. Differential scanning calorimetry analysis of three BPTI-[5,55] variants (A14G, A38V, and A14GA38V) indicated that the A14G mutation stabilized the structure enthalpically, whereas the A38V stabilization was entropy driven. We also determined the structure of the A14GA38V mutant at 1.09 A resolution, whereas the A38V variant did not crystallize, and we previously reported the A14G variant's structure (2ZJX). The overall structures of the A14G and A14GA38V variants were very similar to that of wild-type BPTI, but small local structure perturbations around residues 14 and 38 strongly suggested potential factors contributing to the enthalpy stabilization. First, the A14G mutation displaced the local backbone structures around residues 14 and 38 by up to 0.7 A, presumably increasing local van der Waals interactions. Next, this displacement produced steric clashes between neighboring residue's side-chains in all but the variants containing the A14G mutation. Noteworthy, these clashes are not predicted from the wild type BPTI structure. These observations provide one of the first unambiguous analyses of how a subtle interplay between the sidechain and backbone structures can have a major effect on protein stability.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1097-0134
pubmed:author
pubmed:copyrightInfo
2009 Wiley-Liss, Inc.
pubmed:issnType
Electronic
pubmed:volume
77
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
962-70
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Thermodynamic and structural analysis of highly stabilized BPTIs by single and double mutations.
pubmed:affiliation
Department of Biotechnology and Life Sciences, Graduate School of Engineering, Tokyo University of Agriculture and Technology, Koganei-shi, Tokyo 184-8588, Japan.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't