Interaction of Pig Kidney and Lentil Seedling Copper-Containing Amine Oxidases with Guanidinium Compounds.

The effect of guanidinium compounds on the catalytic mechanism of pig kidney and lentil seedling amine oxidases has been investigated by polarographic techniques and spectroscopy. Guanidine does not inhibit the lentil enzyme and is a weak inhibitor for pig kidney amine oxidase (K(i) =1 mM), whereas aminoguanidine is an irreversible inhibitor of both enzymes, with a K(i) value of 10(-6) M. 1,4-Diguanidino butane (arcaine) is a competitive inhibitor for both pig and lentil amine oxidases. Amiloride is a competitive inhibitor for pig enzyme, but upon prolonged incubation with this drug the enzyme gradually loses its activity in an irreversible manner.