| pubmed-article:19736945 | rdf:type | pubmed:Citation | lld:pubmed |
| pubmed-article:19736945 | lifeskim:mentions | umls-concept:C0243077 | lld:lifeskim |
| pubmed-article:19736945 | lifeskim:mentions | umls-concept:C0165589 | lld:lifeskim |
| pubmed-article:19736945 | pubmed:issue | 41 | lld:pubmed |
| pubmed-article:19736945 | pubmed:dateCreated | 2009-10-13 | lld:pubmed |
| pubmed-article:19736945 | pubmed:abstractText | Extended-spectrum beta-lactamases (ESBLs) are derivatives of enzymes such as SHV-1 and TEM-1 that have undergone site-specific mutations that enable them to hydrolyze, and thus inactivate, oxyimino-cephalosporins, such as cefotaxime and ceftazidime. X-ray crystallographic data provide an explanation for this in that the mutations bring about an expansion of the binding pocket by moving a beta-strand that forms part of the active site wall. Another characteristic of ESBLs that has remained enigmatic is the fact that they are "hypersusceptible" to inhibition by the mechanism-based inactivators tazobactam, sulbactam, and clavulanic acid. Here, we provide a rationale for this "hypersusceptibility" based on a comparative analysis of the intermediates formed by these compounds with wild-type (WT) SHV-1 beta-lactamase and its ESBL variants SHV-2 and SHV-5, which carry the G238S and G238S/E240K substitutions, respectively. A Raman spectroscopic analysis of the reactions in single crystals shows that, compared to WT, the SHV-2 and SHV-5 variants have relatively higher populations of the stable trans-enamine intermediate over the less stable and more easily hydrolyzable cis-enamine and imine co-intermediates. In solution, SHV-2 and SHV-5 also form larger populations of an enamine species compared to SHV-1 as detected by stopped-flow kinetic experiments under single-turnover conditions. Moreover, a simple Raman band shape analysis predicts that the trans-enamine intermediates themselves in SHV-2 and SHV-5 are held in more stable, rigid conformations compared to their trans-enamine analogues in WT SHV-1. As a result of this stabilization, more of the trans-enamine intermediate is formed, which subsequently lowers the K(I) values of the mechanism-based inhibitors up to 50-fold in SHV-2 and SHV-5. | lld:pubmed |
| pubmed-article:19736945 | pubmed:grant | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:grant | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:grant | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:grant | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:language | eng | lld:pubmed |
| pubmed-article:19736945 | pubmed:journal | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:citationSubset | IM | lld:pubmed |
| pubmed-article:19736945 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:chemical | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:19736945 | pubmed:status | MEDLINE | lld:pubmed |
| pubmed-article:19736945 | pubmed:month | Oct | lld:pubmed |
| pubmed-article:19736945 | pubmed:issn | 1520-4995 | lld:pubmed |
| pubmed-article:19736945 | pubmed:author | pubmed-author:CareyPaul RPR | lld:pubmed |
| pubmed-article:19736945 | pubmed:author | pubmed-author:BonomoRobert... | lld:pubmed |
| pubmed-article:19736945 | pubmed:author | pubmed-author:BethelChristo... | lld:pubmed |
| pubmed-article:19736945 | pubmed:author | pubmed-author:KalpMatthewM | lld:pubmed |
| pubmed-article:19736945 | pubmed:issnType | Electronic | lld:pubmed |
| pubmed-article:19736945 | pubmed:day | 20 | lld:pubmed |
| pubmed-article:19736945 | pubmed:volume | 48 | lld:pubmed |
| pubmed-article:19736945 | pubmed:owner | NLM | lld:pubmed |
| pubmed-article:19736945 | pubmed:authorsComplete | Y | lld:pubmed |
| pubmed-article:19736945 | pubmed:pagination | 9912-20 | lld:pubmed |
| pubmed-article:19736945 | pubmed:dateRevised | 2011-9-26 | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:meshHeading | pubmed-meshheading:19736945... | lld:pubmed |
| pubmed-article:19736945 | pubmed:year | 2009 | lld:pubmed |
| pubmed-article:19736945 | pubmed:articleTitle | Why the extended-spectrum beta-lactamases SHV-2 and SHV-5 are "hypersusceptible" to mechanism-based inhibitors. | lld:pubmed |
| pubmed-article:19736945 | pubmed:affiliation | Department of Biochemistry, Molecular Biology and Microbiology, and Medicine,Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA. | lld:pubmed |
| pubmed-article:19736945 | pubmed:publicationType | Journal Article | lld:pubmed |
| pubmed-article:19736945 | pubmed:publicationType | Research Support, U.S. Gov't, Non-P.H.S. | lld:pubmed |
| pubmed-article:19736945 | pubmed:publicationType | Research Support, Non-U.S. Gov't | lld:pubmed |
| pubmed-article:19736945 | pubmed:publicationType | Research Support, N.I.H., Extramural | lld:pubmed |
| http://linkedlifedata.com/r... | pubmed:referesTo | pubmed-article:19736945 | lld:pubmed |
| http://linkedlifedata.com/r... | pubmed:referesTo | pubmed-article:19736945 | lld:pubmed |
