Using enzyme inhibitors to determine the mechanism of extracellular peptidases in fresh and estuarine waters
Abstract
Enzymatic hydrolys is a process in which enzymes catalyze the cleavage of bonds in molecules with the addition of water. Microbes produce extracellular enzymes and secrete them outside the cell membrane to break down complex chemical structures. These enzymes yield energy and nutrients for their parent organisms and also catalyze the cycling of organic matter in ecosystems. The Malcolm X Shabazz BioGeoChemistry team in cooperation with University of Tennessee researchers conducted primary field studies from various water resources in the Pocono Mountains each year from 2013-2019. Most studies of extracellular enzymes in the environment assume that each substrate is hydrolyzed by the corresponding enzyme for instance that hydrolysis of leucine-aminomethylcoumarin results from the activity of leucyl amino-peptidase. However, enzymes found in water hydrolyze a range of substrates. Extracellular enzyme activity were compared and tested by inhibition in water from natural sources like the Delaware River, and several ponds and creeks in the Pocono Valley. An experiment was conducted using three substrates: Leucine-AMC, Arginine-AMC, and Gly-Gly-Arg AMC (ggr). Inhibitors such as E64, an inhibitor for cysteine peptidases and EDTA, an inhibitor for metallopeptidases, were added to assess the functional mechanism of enzymes present in these water bodies. The team looked at the relative fluorescence and rates of enzyme activities at the different water sites in the pocono valley and compared these metrics in inhibited and uninhibited samples. We conclude EDTA and E64 did inhibit the peptidases naturally present in these water bodies, indicating that both cysteine peptidases and metallopeptidases contributed to observe enzyme activity. In uninhibited samples trypsin was most active across water samples. This is the fifth year of our studies collecting usable data about several different types of protein enzymes and more studies will have to be undertaken to better understand the specificity of peptidases.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMED41B1052M
- Keywords:
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- 0805 Elementary and secondary education;
- EDUCATION