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Ein Beitrag zum Funktionsmechanismus der ureatischen Harnstoffspaltung

1972; Elsevier BV; Volume: 163; Issue: 1 Linguagem: Inglês

10.1016/s0015-3796(17)31206-4

0015-3796

A. Barth, H. Michel,

Enzyme function and inhibition

The kinetic analysis of the activity of the 12 S-unit of urease showed a characteristic dependence of Km and Vmax on pH in a solution free of buffer. The results suggested the participation of an imidazole residue of histidine in addition to carboxyl and thiol groups in the catalytic process. This was concluded from the variation of the pKm values in dependence on pH and from the inhibition of the enzymic activity by use of histidine specific agents. The interpretation of the results suggested a possible mechanism for the urease - catalyzed hydrolysis of urea with the support of the functional groups, obtained, at the active centre of this enzyme.