Kinetic Characterization of β-Glucuronidase from B. dorei and Studies on the Response and Growth of Bacteria in Estriol and Diclofenac Glucuronides
Public Deposited- Last Modified
- February 26, 2019
- Creator
-
Bahethi, Rohini R.
- Affiliation: College of Arts and Sciences, Department of Chemistry
- Abstract
- The common colon cancer drug CPT-11 and its active metabolite SN-38 have a dose-limiting side effect of severe diarrhea in patients. The dose-limiting side effects of CPT-11 arise when the metabolite SN-38G is reactivated in the intestines by β-glucuronidases (GUS) from bacteria. Previous work found selective inhibitors that bind to a loop region near the active site in different species and are effective in alleviating CPT-11 induced diarrhea in mice. The GUS from Bacteroides dorei does not have this loop. We sought to kinetically characterize the processing of SN-38G by this GUS and compare it with other GUS enzymes from common bacteria. We found that GUS from B. dorei was less effective than enzymes from other bacteria, however it did process SN-38G with a Km of 21±2 μM and a kcat of 5.9±0.2 s-1. Therefore, new inhibitors may need to be designed that do not require an active site loop for have maximal chemotherapeutic effectiveness against CPT-11 induced diarrhea. We also attempted to characterize the response and growth of Escherichia coli in the glucuronidated forms of Diclofenac and estriol. From this, we determined that higher than 25 μM and 100 nM of substrate, respectively are necessary to maintain growth.
- Date of publication
- autumn 2016
- Keyword
- DOI
- Resource type
- Rights statement
- In Copyright
- Note
- Funding: None
- Advisor
- Redinbo, Matthew R.
- Degree
- Bachelor of Arts
- Academic concentration
- Chemistry
- Honors level
- Honors
- Degree granting institution
- University of North Carolina at Chapel Hill
- Graduation year
- 2017
- Language
- English
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This work has no parents.
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