Proton inventories constitute reliable tools in investigating enzymatic mechanisms: Application on a novel thermo-stable extracellular protease from a halo-alkalophilic Bacillus sp.

dc.contributor.authorTheodorou, L. G.en
dc.contributor.authorPerisynakis, A.en
dc.contributor.authorValasaki, K.en
dc.contributor.authorDrainas, C.en
dc.contributor.authorPapamichael, E. M.en
dc.date.accessioned2015-11-24T16:45:42Z
dc.date.available2015-11-24T16:45:42Z
dc.identifier.issn0021-924X-
dc.identifier.urihttps://olympias.lib.uoi.gr/jspui/handle/123456789/8972
dc.rightsDefault Licence-
dc.subjectcysteine proteinasesen
dc.subjectenzyme kineticsen
dc.subjectenzyme mechanismsen
dc.subjecthalo-alkalophilesen
dc.subjectproton inventoriesen
dc.subjectpapain-catalyzed hydrolysesen
dc.subjectcysteine proteinasesen
dc.subjectactive-siteen
dc.subjectinhibitoren
dc.subjectelectrophoresisen
dc.subjectpurificationen
dc.subjectpeptidasesen
dc.subjectdependenceen
dc.subjectkineticsen
dc.subjectinsighten
dc.titleProton inventories constitute reliable tools in investigating enzymatic mechanisms: Application on a novel thermo-stable extracellular protease from a halo-alkalophilic Bacillus sp.en
heal.abstractA novel protease designated protease-A-17N-1, was purified from the haloalkalophilic Bacillus sp. 17N-1, and found active in media containing dithiothreitol and EDTAK(2). This enzyme maintained significant activity from pH 6.00 to 9.00, showed optimum k(cat)/K-m value at pH 7.50 and 33 degrees C. It was observed that only specific inhibitors of cysteine proteinases inhibited its activity. The pH-(k(cat)/K-m) profile of protease-A-17N-1 was described by three pK(a)s in the acid limb, and one in the alkaline limb. Both are more likely due t3o the protonic dissociation of an acidic residue, and the development and subsequent deprotonation of an ion-pair, respectively, in its catalytic site, characteristic for cysteine proteinases. Moreover, both the obtained estimates of rate constant k(1) and the ratio k(2)/k(-1) at 25 degrees C, from the temperature-(k(cat)/K-m) profile of protease-A-17N-1, were found similar to those estimated from the proton inventories of the same parameter, verifying the reliability of the latter methodology. Besides, the bowed-downward proton inventories of k(cat)/K-m, as well as the large inverse SIE observed for this parameter, in combination with its dependence versus temperature, were showed unambiguously that k(cat)/K-m = k(1). Such results suggest that the novel enzyme is more likely to be a cysteine proteinase functioning via a general acid-base mechanism.en
heal.accesscampus-
heal.fullTextAvailabilityTRUE-
heal.identifier.primaryDoi 10.1093/Jb/Mvm132-
heal.identifier.secondary<Go to ISI>://000251645900017-
heal.identifier.secondaryhttp://jb.oxfordjournals.org/content/142/2/293.full.pdf-
heal.journalNameJ Biochemen
heal.journalTypepeer reviewed-
heal.languageen-
heal.publicationDate2007-
heal.publisherThe Japanese Biochemical Societyen
heal.recordProviderΠανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείαςel
heal.typejournalArticle-
heal.type.elΆρθρο Περιοδικούel
heal.type.enJournal articleen

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