Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases
| Main Author: | |
|---|---|
| Language: | English |
| Published: |
Case Western Reserve University School of Graduate Studies / OhioLINK
2009
|
| Subjects: | |
| Online Access: | http://rave.ohiolink.edu/etdc/view?acc_num=case1228504500 |
| id |
ndltd-OhioLink-oai-etd.ohiolink.edu-case1228504500 |
|---|---|
| record_format |
oai_dc |
| spelling |
ndltd-OhioLink-oai-etd.ohiolink.edu-case12285045002021-08-03T05:32:55Z Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases Kalp, Matthew Douglas Biochemistry Biophysics SHV-1 Beta-lactamase tazobactam sulbactam clavulanate clavulanic acid mechanism-based inhibitors Raman spectroscopy Raman crystallography <p>Raman spectroscopy involves analyzing inelastically scattered photons from a laser beam that is focused into the sample of interest. The laser light interacts with the sample, which results in the energy of the laser photons being shifted up or down. The shift in energy—the Raman spectrum—provides information on molecular vibrations that, in turn, yield data on molecular conformation, electronic distribution, and environment. At its most effective, Raman spectroscopy can provide exquisite detail from an important site or molecule in a much larger macromolecular complex.</p><p>In this work, Raman crystallography is used to described the reaction pathway between small molecule inhibitors and class A β-lactamases. β-lactamases are enzymes (EC 3.5.2.6) produced by both Gram-negative and Gram-positive bacteria and are responsible for their resistance to β-lactam antibiotics, such as penicillins, cephalosporins, and carbapenems. These antibiotics have a common ring structure, known as a β-lactam, which consists of three carbon atoms and one nitrogen atom. The lactamase enzymes are hydrolases that break the ring open, deactivating the molecule's antibacterial properties. Substrates, such as penicillins and 1st and 2nd generation cephalosporins, are rapidly hydrolyze by the majority of β-lactamases. Only inhibitors, such as penam sulfones, form a transiently stable acyl-enzyme with the β-lactamase, which effectively prevents the enzyme from hydrolyzing other β-lactams. Most inhibitors—penam sulfones, clavams, carbapenems, and cephalosporins—undergo secondary reactions inside the enzyme. This results in multiple reaction intermediates and, despite intense research efforts, it is still unclear which species is responsible for the clinical utility of these compounds.</p><p>This work will describe the reaction pathways for various inhibitors with SHV β-lactamase and its variants by Raman difference spectroscopy in single protein crystals. In this method, one measures an enzyme spectrum and the spectrum of an enzyme complexed with ligand. Subtraction of the two yields the spectrum of the bound ligand and any conformation changes in the protein that occur upon complexation. With the ability to probe unique molecular structures and conformations, Raman crystallography is ideal for identifying and observing populations and kinetic behavior of reaction intermediates and intermediates constituting less than 30% active site occupancy.</p> 2009 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1228504500 http://rave.ohiolink.edu/etdc/view?acc_num=case1228504500 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 Biophysics SHV-1 Beta-lactamase tazobactam sulbactam clavulanate clavulanic acid mechanism-based inhibitors Raman spectroscopy Raman crystallography |
| spellingShingle |
Biochemistry Biophysics SHV-1 Beta-lactamase tazobactam sulbactam clavulanate clavulanic acid mechanism-based inhibitors Raman spectroscopy Raman crystallography Kalp, Matthew Douglas Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases |
| author |
Kalp, Matthew Douglas |
| author_facet |
Kalp, Matthew Douglas |
| author_sort |
Kalp, Matthew Douglas |
| title |
Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases |
| title_short |
Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases |
| title_full |
Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases |
| title_fullStr |
Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases |
| title_full_unstemmed |
Raman Crystallographic Studies of Inhibitor Reactions in Class A β-Lactamases |
| title_sort |
raman crystallographic studies of inhibitor reactions in class a β-lactamases |
| publisher |
Case Western Reserve University School of Graduate Studies / OhioLINK |
| publishDate |
2009 |
| url |
http://rave.ohiolink.edu/etdc/view?acc_num=case1228504500 |
| work_keys_str_mv |
AT kalpmatthewdouglas ramancrystallographicstudiesofinhibitorreactionsinclassablactamases |
| _version_ |
1719421592042209280 |