Interaction of ethanolamine with alcohol dehydrogenase from the horse liver
Ostrovskiĭ, S.I.; Artsukevich, I.M.
Biokhimiia 54(11): 1888-1893
1989
ISSN/ISBN: 0320-9725 PMID: 2627556 Document Number: 335046
The pattern of kinetic behaviour of ethanolamine (EA), an ethanol structural analog, in the alcohol dehydrogenase reaction has been studied. EA has been shown to manifest a mixed type inhibition versus ethanol and a noncompetitive behaviour towards the second substrate, NAD. A graphical analysis of the experimental results as well as the construction of secondary graphs provide evidence in favour of a mechanism, according to which the interaction between EA and the enzyme results in a dead-end complex formation (ESI). A direct conversion into reaction products can be achieved only after EA separation from the complex. The Ki value for the E-EA complex is 1.3 mM; that for EA release from the E-EA is 1.8 mM. An analysis of competitive interactions with NAD showed these constants to be equal in values (2 mM). Taking account of real concentrations of tissue EA and of experimental values of Ki, a conclusion is drawn on possible participation of EA in the alcohol dehydrogenase reaction control.