Linked Life Data

21238457

Source:http://linkedlifedata.com/resource/pubmed/id/21238457

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2011-2-21
pubmed:abstractText
?-Lactamase inhibitory protein (BLIP) binds and inhibits a diverse collection of class A ?-lactamases. Widespread resistance to ?-lactam antibiotics currently limits the treatment strategies for Staphylococcus infections. The goals of this study were to determine the binding affinity of BLIP for Staphylococcus aureus PC1 ?-lactamase and to identify mutants that alter binding affinity. The BLIP inhibition constant (K(i)) for PC1 ?-lactamase was measured at 350 nM, and isothermal titration calorimetry experiments indicated a binding constant (K(d)) of 380 nM. Twenty-three residue positions in BLIP that contact ?-lactamase were randomized, and phage display was used to sort the libraries for tight binders to immobilized PC1 ?-lactamase. The BLIP(K74G) mutant was the dominant clone selected, and it was found to inhibit the PC1 ?-lactamase with a K(i) of 42 nM, while calorimetry indicated a K(d) of 26 nM. Molecular modeling studies suggested that BLIP binds weakly to the PC1 ?-lactamase due to the presence of alanine at position 104 of PC1. This position is occupied by glutamate in the TEM-1 enzyme, where it forms a salt bridge with the BLIP residue Lys74 that is important for the stability of the complex. This hypothesis was confirmed by showing that the PC1(A104E) enzyme binds BLIP with 15-fold greater affinity than wild-type PC1 ?-lactamase. Kinetic measurements indicated similar association rates for all complexes with variation in affinity due to altered dissociation rate constants, suggesting that changes in short-range interactions are responsible for the altered binding properties of the mutants.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
1089-8638
pubmed:author
pubmed:copyrightInfo
Copyright © 2011 Elsevier Ltd. All rights reserved.
pubmed:issnType
Electronic
pubmed:day
11
pubmed:volume
406
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
730-44
pubmed:dateRevised
2011-9-26
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Identification of a ?-lactamase inhibitory protein variant that is a potent inhibitor of Staphylococcus PC1 ?-lactamase.
pubmed:affiliation
Department of Pharmacology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural