title: Inactivation of recombinant human steroid sulfatase by KW-2581.
abstract: Steroid sulfatase (STS) catalyses the hydrolysis of the sulfate esters of 3-hydroxy steroids, which are inactive transport or precursor forms of the active 3-hydroxy steroids. STS inhibitors are expected to block the local production and, consequently to reduce the active steroid levels; therefore, they are considered as potential new therapeutic agents for the treatment of estrogen- and androgen-dependent disorders such as breast and prostate cancers. KW-2581 is a novel steroidal STS inhibitor. In the present study, we found KW-2581 inhibited recombinant human STS (rhSTS) activity with an IC(50) of 2.9 nM when estrone sulfate was used as a substrate. The potency of KW-2581 was approximately 5-fold higher than that of a non-steroidal STS inhibitor, 667 COUMATE. KW-2581 was able to equally inhibit rhSTS activity when dehydroepiandrosterone sulfate was used as another substrate. KW-2581 inhibited rhSTS activity in a time- and concentration-dependent manner (k(inact), 0.439 min(-1); K(i, app), 15 nM), suggesting that it is an active site-directed irreversible inhibitor. Both decrease of KW-2581 concentration and increase of the des-sulfamoylated form's concentration were simultaneously observed during the reaction in a time-dependent manner with corresponding to the decrease of STS activity. Our findings for the first time demonstrated the production of des-sulfamoylated form of the compound as a consequence of STS inactivation.
authors.affiliation: Pharmaceutical Research Center, Kyowa Hakko Kogyo Co. Ltd., 1188 Shimotogari, Nagaizumi-cho, Sunto-gun, Shizuoka, Japan. hiroyuki.ishida@kyowa.co.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ishida
authors.forename: Natsuko
authors.initials: N
authors.lastname: Sato
authors.forename: Jun
authors.initials: J
authors.lastname: Hosogi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuwabara
mesh_terms: D003374:Coumarins / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D004789:Enzyme Activation / Q000187:drug effects; D004958:Estradiol / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D008954:Models, Biological; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D043266:Steryl-Sulfatase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013431:Sulfates / Q000378:metabolism; D013449:Sulfonamides / Q000493:pharmacokinetics / Q000494:pharmacology*; D013451:Sulfonic Acids
chemical_list: D003374:Coumarins; C524251:KW 2581; D011994:Recombinant Proteins; D013431:Sulfates; D013449:Sulfonamides; D013451:Sulfonic Acids; C520511:irosustat; D004958:Estradiol; D043266:Steryl-Sulfatase