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Enzyme Kinetics of PAPS-Sulfotransferase
1Department of Medicinal Chemistry, University of Florida, Gainesville, FL, USA. mojames@ufl.edu.
Methods in Molecular Biology (Clifton, N.J.)
|July 17, 2021
Summary
Human cytosolic sulfotransferase (SULT) enzymes, crucial for drug metabolism, exhibit complex kinetics and structural features. Their regulation involves protein dimerization, flexible loops, and cysteine residue modifications, impacting drug and PAPS binding.
Area of Science:
- Biochemistry
- Enzymology
- Pharmacology
Background:
- Cytosolic sulfotransferase (SULT) enzymes are vital in human tissues like the liver and kidney.
- They catalyze the transfer of a sulfo group from PAPS to various drug substrates.
- SULTs play a significant role in drug metabolism and detoxification.
Purpose of the Study:
- To elucidate the function, tissue distribution, and structural characteristics of human SULT enzymes.
- To present examples of SULT enzyme kinetics with diverse substrates.
- To highlight regulatory mechanisms influencing SULT activity.
Main Methods:
- Analysis of SULT enzyme structure and function.
- Investigation of tissue distribution.
- Enzyme kinetics studies with varying substrate concentrations.
- Examination of regulatory mechanisms like oxidation-reduction.
Main Results:
- SULTs form stable dimers with conserved domains.
- Flexible loops near the dimerization domain act as gates modulating substrate access.
- Cysteine residue redox state influences substrate and PAPS/PAP binding.
- SULT kinetics often exhibit substrate inhibition at higher concentrations.
Conclusions:
- Human SULT enzymes possess intricate structural and regulatory features essential for their function in drug metabolism.
- Understanding these properties is key to predicting drug responses and developing new therapies.
- Further research into SULT regulation can offer insights into personalized medicine.
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