A major aspect of the pharmacology of drugs is the modification of their action and duration of action via biotransformation and excretion. Sulfation is one of the major pathways for the biotransformation and excretion of drugs as well as endogenous compounds such as steroids and catecholamines. The long-term objective of this research is to understand the role of sulfation in the metabolism of drugs and endogenous substrates in humans. As observed for other drug metabolizing enzymes such as the glutathione S-transferases and UDP-glucuronyltransferases, sulfotransferases, the enzymes catalyzing the transfer of the sulfate moiety to an acceptor compound, represent a family of distinct isoenzymes. However, in humans the number, characteristics and relationships of these enzymes are not well known. The research proposed in this application is directed toward investigating the protein chemistry and molecular biology of human phenol sulfotransferases. Human blood platelets, provide an accessible source of two forms of phenol sulfotransferase (PST) activity, the phenol (P) and catecholamine (M) PST activities. Investigation of the platelet PSTs may provide valuable insights into the role of sulfation in less accessible human tissues. Platelet PST activity may also serve as an indicator for the whole body metabolism of a given drug by sulfation. The goals of the proposed research are designed to investigate the biochemistry of the PSTs at the levels of their enzymic activity, protein chemistry, and molecular biology. First, the P- and M-PST activities in platelets will be purified and characterized. Purification techniques will include ChromatofocusingR, affinity chromatography, and specific antibody recognition. The P and M PST activities in platelets are believed to be catalyzed by different enzymes and are also very similar kinetically to PST activities in other tissues and organs indicating that these two enzymes are widely distributed in the body. Second, specific antibodies will be raised in rabbits against the purified PSTs. These antibodies will be used to identify and immunoquantitate the presence of PST proteins. Third, cDNAs encoding the two enzymes will be cloned. Antibodies raised against the two purified PSTs will be used to isolate the respective cDNAs from lambda gtll cDNA libraries. Since platelets are enucleated, lambda gtll libraries generated from human brain and liver will be used. cDNAs obtained from these libraries will be characterized so that they may serve as probes to study the regulation, heterogeneity, and structure of human PSTs.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
5R29GM038953-04
Application #
3466570
Study Section
Pharmacology A Study Section (PHRA)
Project Start
1987-07-01
Project End
1992-06-30
Budget Start
1990-07-01
Budget End
1991-06-30
Support Year
4
Fiscal Year
1990
Total Cost
Indirect Cost
Name
University of Rochester
Department
Type
Schools of Dentistry
DUNS #
208469486
City
Rochester
State
NY
Country
United States
Zip Code
14627
Tibbs, Zachary E; Rohn-Glowacki, Katie Jo; Crittenden, Frank et al. (2015) Structural plasticity in the human cytosolic sulfotransferase dimer and its role in substrate selectivity and catalysis. Drug Metab Pharmacokinet 30:3-20
Wang, Ting; Cook, Ian; Falany, Charles N et al. (2014) Paradigms of sulfotransferase catalysis: the mechanism of SULT2A1. J Biol Chem 289:26474-80
Rohn-Glowacki, Katie Jo; Falany, Charles N (2014) The potent inhibition of human cytosolic sulfotransferase 1A1 by 17?-ethinylestradiol is due to interactions with isoleucine 89 on loop 1. Horm Mol Biol Clin Investig 20:81-90
Cook, Ian; Wang, Ting; Almo, Steven C et al. (2013) The gate that governs sulfotransferase selectivity. Biochemistry 52:415-24
Leyh, Thomas S; Cook, Ian; Wang, Ting (2013) Structure, dynamics and selectivity in the sulfotransferase family. Drug Metab Rev 45:423-30
Cook, Ian; Wang, Ting; Falany, Charles N et al. (2013) High accuracy in silico sulfotransferase models. J Biol Chem 288:34494-501
Falany, Charles N; Rohn-Glowacki, Katie Jo (2013) SULT2B1: unique properties and characteristics of a hydroxysteroid sulfotransferase family. Drug Metab Rev 45:388-400
Cook, Ian; Wang, Ting; Almo, Steven C et al. (2013) Testing the sulfotransferase molecular pore hypothesis. J Biol Chem 288:8619-26
Rohn, Katie Jo; Cook, Ian T; Leyh, Thomas S et al. (2012) Potent inhibition of human sulfotransferase 1A1 by 17ýý-ethinylestradiol: role of 3'-phosphoadenosine 5'-phosphosulfate binding and structural rearrangements in regulating inhibition and activity. Drug Metab Dispos 40:1588-95
Salman, Emily D; He, Dongning; Runge-Morris, Melissa et al. (2011) Site-directed mutagenesis of human cytosolic sulfotransferase (SULT) 2B1b to phospho-mimetic Ser348Asp results in an isoform with increased catalytic activity. J Steroid Biochem Mol Biol 127:315-23

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