Imikhiqizo

Ama-activators e-Carbonic anhydrase: isifundo sokuqala sokwenza kusebenze i-isoform VI eyimfihlo yomuntu enama-amino acid nama-amine.

I-secretory isozyme ye-human carbonic anhydrase (hCA, EC 4.2.1.1), i-hCA VI, yenziwe yakhiwe, yavezwa, futhi yahlanzwa ohlelweni lokubonisa amagciwane.Amapharamitha we-kinetic we-CO(2) hydration reaction afakazele i-hCA VI ukuba ne-ak(ikati) lika-3.4 x 10(5)s(-1) kanye no-k(ikati)/K(M) lokungu-4.9 x 10(7)M (-1)s(-1) (ku-pH 7.5 kanye no-20 degrees C).I-hCA VI inomsebenzi obalulekile we-catalytic wokusabela komzimba, wokuhleleka okufanayo kobukhulu njenge-isoform yasendaweni yonke i-CA I noma i-transmembrane, isozyme ehlobene nesimila CA IX.Uchungechunge lwama-amino acid nama-amine aboniswe ukuthi asebenze njengezicuphi ze-CA VI, ezisebenza ngokuguquguqukayo.I-l-His, i-l-Trp, ne-dopamine ibonise imiphumela ebuthakathaka ye-CA VI (K(A)s ebangeni le-21-42 microM), kanti i-d-His, d-Phe, l-DOPA, l-Trp, i-serotonin , futhi amanye ama-pyridyl-alkylamine abe ama-activator angcono, ane-K(A)s ebangeni le-13-19 microM.Ama-activator e-CA VI ahamba phambili kube yi-l-Phe, d-DOPA, l-Tyr, 4-amino-l-Phe, ne-histamine, nama-K(A)s kububanzi obungu-1.23-9.31 microM.Zonke lezi zivuseleli zithuthukisa i-k(ikati), azinawo umthelela ku-K(M), zibambe iqhaza ngaleyo ndlela esinyathelweni esinqumayo somjikelezo we-catalytic, ukusabela kokudlulisa i-proton phakathi kwesizinda se-enzyme esebenzayo nendawo ezungezile.