Show simple item record

dc.contributorWichita State University. Department of Chemistryen_US
dc.contributor.authorDharmasena, Sanjeewa P.en_US
dc.contributor.authorWimalasena, D. Shyamalien_US
dc.contributor.authorWimalasena, Kandategeen_US
dc.date.accessioned2012-02-06T17:15:28Z
dc.date.available2012-02-06T17:15:28Z
dc.date.issued2002-10-15en_US
dc.identifier12369831en_US
dc.identifier0370623en_US
dc.identifierbi0262606en_US
dc.identifierGM45026en_US
dc.identifier.citationBiochemistry. 2002 Oct 15; 41(41): 12414-20.en_US
dc.identifier.issn0006-2960en_US
dc.identifier.urihttp://hdl.handle.net/10057/4241
dc.descriptionFull text of this article is not available in SOAR.en_US
dc.description.abstractThe steady-state kinetic data show that 3-hydroxy-4-phenylthiazole-2(3H)-thione (3H4PTT) is a potent tight-binding inhibitor for dopamine beta-monooxygenase (DbetaM) with a dissociation constant of 0.9 nM. Ackermann-Potter plots of the enzyme dependence of the inhibition revealed that the stoichiometry of the enzyme inhibition by 3H4PTT is 1:1. Pre-steady-state progress curves at varying inhibitor with fixed reductant and enzyme concentrations clearly show the slow binding behavior of the inhibitor. The observed kinetic behavior is consistent with the apparent direct formation of the tightly bound E x I* complex. The k(on) and k(off) for 3H4PTT which were determined under pre-steady-state conditions at variable inhibitor concentrations were found to be (1.85 +/- 0.07) x 10(6) M(-1) s(-1) and (1.9 +/- 0.6) x 10(-3) s(-1), respectively. The dissociation constant calculated from these rates was similar to that determined under steady-state conditions, confirming that 3H4PTT is a kinetically well-behaved inhibitor. The steady-state as well as pre-steady-state kinetic studies at variable DMPD concentrations show that the inhibition is competitive with respect to the reductant, demonstrating the exclusive interaction of 3H4PTT with the oxidized form of the enzyme. The kinetic behavior and the structural properties of 3H4PTT are consistent with the proposal that the E x 3H4PTT complex may mimic the transition state for the product (protonated) release step of the enzyme. Therefore, 3H4PTT could be used as a convenient probe to examine the properties of the E x P complex of the DbetaM reaction and also as an active site titrant for the oxidized enzyme.en_US
dc.description.sponsorshipNIGMS NIH HHSen_US
dc.format.extent12414-20en_US
dc.language.isoengen_US
dc.publisherAmerican Chemical Societyen_US
dc.relation.ispartofseriesBiochemistryen_US
dc.relation.ispartofseriesBiochemistryen_US
dc.sourceNLMen_US
dc.subjectResearch Support, U.S. Gov't, P.H.S.en_US
dc.subject.meshAnimalsen_US
dc.subject.meshBinding, Competitiveen_US
dc.subject.meshCattleen_US
dc.subject.meshChelating Agents/chemistryen_US
dc.subject.meshCopper/chemistryen_US
dc.subject.meshDopamine beta-Hydroxylase/antagonists & inhibitorsen_US
dc.subject.meshDose-Response Relationship, Drugen_US
dc.subject.meshEnzyme Inhibitors/chemistryen_US
dc.subject.meshKineticsen_US
dc.subject.meshModels, Chemicalen_US
dc.subject.meshProtein Bindingen_US
dc.subject.meshSpectrophotometry, Ultraviolet/chemistryen_US
dc.subject.meshThiazoles/chemistryen_US
dc.subject.meshThiones/chemistryen_US
dc.subject.meshDopamine beta-Hydroxylase/chemistryen_US
dc.titleA slow-tight binding inhibitor of dopamine beta-monooxygenase: a transition state analogue for the product release stepen_US
dc.typeArticleen_US
dc.coverage.spacialUnited Statesen_US
dc.description.versionpeer revieweden_US
dc.rights.holderCopyright © 2002 American Chemical Societyen_US


Files in this item

FilesSizeFormatView

There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record