{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,16]],"date-time":"2026-03-16T11:51:45Z","timestamp":1773661905107,"version":"3.50.1"},"reference-count":0,"publisher":"American Society for Microbiology","issue":"8","license":[{"start":{"date-parts":[[1995,8,1]],"date-time":"1995-08-01T00:00:00Z","timestamp":807235200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Antimicrob Agents Chemother"],"published-print":{"date-parts":[[1995,8]]},"abstract":"<jats:p>To examine the effect of disruption of the salt bridge (between Arg-164 and Asp-179 [numbering of Ambler et al. (Biochem J. 267:269-272, 1991)]) that anchors the conserved omega-loop in class A beta-lactamases, we obtained mutant enzymes with each of the 19 other amino acid residues replacing Asp-179 in the TEM beta-lactamase encoded by pUC19 and studied the level of resistance to various beta-lactams conferred by each enzyme. All mutations of Asp-179 compromised the level of resistance to ampicillin, but most of them enhanced resistance to ceftazidime. In contrast, mutations of Asp-179 generally impaired the low levels of resistance to cefepime and aztreonam. One might expect to find clinical isolates with mutant TEM beta-lactamases with replacements of Asp-179 that express an expanded spectrum of resistance to beta-lactams including ceftazidime.<\/jats:p>","DOI":"10.1128\/aac.39.8.1878","type":"journal-article","created":{"date-parts":[[2012,6,28]],"date-time":"2012-06-28T00:06:25Z","timestamp":1340841985000},"page":"1878-1880","update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":36,"title":["Effects of Asp-179 mutations in TEMpUC19 beta-lactamase on susceptibility to beta-lactams"],"prefix":"10.1128","volume":"39","author":[{"given":"S B","family":"Vakulenko","sequence":"first","affiliation":[{"name":"Department of Medicine, Wayne State University, Detroit, Michigan 48202, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"T\u00f3th","sequence":"additional","affiliation":[{"name":"Department of Medicine, Wayne State University, Detroit, Michigan 48202, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P","family":"Taibi","sequence":"additional","affiliation":[{"name":"Department of Medicine, Wayne State University, Detroit, Michigan 48202, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S","family":"Mobashery","sequence":"additional","affiliation":[{"name":"Department of Medicine, Wayne State University, Detroit, Michigan 48202, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S A","family":"Lerner","sequence":"additional","affiliation":[{"name":"Department of Medicine, Wayne State University, Detroit, Michigan 48202, USA."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"235","container-title":["Antimicrobial Agents and Chemotherapy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.39.8.1878","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/AAC.39.8.1878","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,2,21]],"date-time":"2022-02-21T20:01:02Z","timestamp":1645473662000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/AAC.39.8.1878"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1995,8]]},"references-count":0,"journal-issue":{"issue":"8","published-print":{"date-parts":[[1995,8]]}},"alternative-id":["10.1128\/AAC.39.8.1878"],"URL":"https:\/\/doi.org\/10.1128\/aac.39.8.1878","relation":{},"ISSN":["0066-4804","1098-6596"],"issn-type":[{"value":"0066-4804","type":"print"},{"value":"1098-6596","type":"electronic"}],"subject":[],"published":{"date-parts":[[1995,8]]},"assertion":[{"value":"1995-08-01","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}