Logo image
Back
On the Mechanism of Aryl Sulfotransferase
Journal article   Open access   Peer reviewed

On the Mechanism of Aryl Sulfotransferase

Michael W Duffel and William B Jakoby
The Journal of biological chemistry, Vol.256(21), pp.11123-11127
01/01/1981
DOI: 10.1016/S0021-9258(19)68565-0
PMID: 6945304
url
https://doi.org/10.1016/S0021-9258(19)68565-0View
Published (Version of record) Open Access

Abstract

Aryl sulfotransferase IV (EC 2.8.2.1), purified to homogeneity from male rat liver, catalyzes the sulfation of a variety of substituted phenols, including catecholamines, tyrosine esters, and peptides containing NH sub(2)-terminal tyrosine residues. An investigation of the mechanism of the enzyme was carried out using 2-chloro-4-nitrophenol as a model substrate. Kinetic, inhibition, and binding studies with aryl sulfotransferase IV are all consistent with a random rapid equilibrium Bi Bi kinetic mechanism with two dead end product inhibitor complexes. Studies of the chemical mechanisms of the enzyme-catalyzed reaction demonstrate that electron-withdrawing substituents decrease the maximal velocity of phenol sulfation. The maximal velocity of the reaction correlates with Hammett sigma sub(p) super(-) constants ( rho = -0.25). Evidence is presented for the mechanism by which adenosine 3',5'-bisphosphate and aryl sulfotransferase catalyze the transfer of sulfate from 2-chloro-4-nitrophenyl sulfate to other phenols.
 aryl sulfotransferase liver mechanisms rats

Details

Metrics

7 Record Views
120 Times Cited - Web of Science
Logo image