RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES

RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES

Bibliographic Details
Main Author: Che, Tao
Language:English
Published: Case Western Reserve University School of Graduate Studies / OhioLINK 2015
Subjects:
Biochemistry
Chemistry
Microbiology
Bacteria resistance
beta-lactamase
carboxylation
decarboxylation
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=case1421514785
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-case14215147852021-08-03T06:29:05Z RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES Che, Tao Biochemistry Chemistry Microbiology Bacteria resistance beta-lactamase carboxylation decarboxylation The driving force behind my research is the need to develop improved antibiotic therapies to combat the drug resistance. The production of ß-lactamase is the major cause of failure of ß-lactam-based therapy against Gram-negative bacteria, such as Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. However, currently there are only three ß-lactamase inhibitors in clinical use and they narrowly target the class A enzymes. A clinically useful inhibitor needs to have a significantly broader inhibitory spectrum, ideally targeting all serine ß-lactamases (class A, C and D).My work is focused on studying the catalytic mechanisms of serine ß-lactamases, and thence aiding in the design new mechanism-based inhibitors. A major thrust involves use of Raman spectroscopy which is a laser light scattering technique that provides structural information of the bound ligand in the active site of the enzymes in real time. With the combination of Raman spectroscopy and other structural or microbiological methodologies, we aim to address two fundamental questions in drug discovery: 1) why is a compound a good inhibitor for a target enzyme in vitro? 2) how effectively is a drug taken up by cells?We have designed and implemented a new method by combining rapid mix-rapid freeze of aqueous solution with Raman spectroscopy. This enables us to trap intermediates early on the reaction pathway- within milliseconds. By studying the reaction of OXA-24 and OXA-1 and a penicillin derivative inhibitor in crystallo and in solution, we have shown that carboxylation of the lysine is critical for class D enzymes' catalysis, while decarboxylation can be induced by inhibitors and therefore, leading to enzyme inactivation.Penetration barriers and efflux pumps are two major mechanisms bacteria adopt to exclude drug molecules. The difficulty in directly measuring compound penetration is a major reason for the lack of progress in antibiotic discovery. Using a new protocol, the intermediates or products formed inside the bacterial cells have been captured, which allows us to investigate reactions inside bacterial cells. 2015-06-03 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1421514785 http://rave.ohiolink.edu/etdc/view?acc_num=case1421514785 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Biochemistry
Chemistry
Microbiology
Bacteria resistance
beta-lactamase
carboxylation
decarboxylation
spellingShingle Biochemistry
Chemistry
Microbiology
Bacteria resistance
beta-lactamase
carboxylation
decarboxylation
Che, Tao
RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES
author Che, Tao
author_facet Che, Tao
author_sort Che, Tao
title RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES
title_short RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES
title_full RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES
title_fullStr RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES
title_full_unstemmed RAMAN SPECTROSCOPIC STUDIES OF INHIBITOR REACTIONS IN CLASS A, B AND D beta-LACTAMASES
title_sort raman spectroscopic studies of inhibitor reactions in class a, b and d beta-lactamases
publisher Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate 2015
url http://rave.ohiolink.edu/etdc/view?acc_num=case1421514785
work_keys_str_mv AT chetao ramanspectroscopicstudiesofinhibitorreactionsinclassabanddbetalactamases
_version_ 1719437567739297792

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