Cysteamine oxidation by lentil seedling amine oxidase.
Cysteamine is oxidatively deaminated by lentil amine oxidase. It shows saturation kinetic K(m) = 9 x 10(-4) M like other substrates, but the aldehyde produced leads to loss of enzyme activity, which is restored by dialysis. When putrescine is the substrate of the amine oxidase cysteamine behaves like a competitive inhibitor, and shows Ki = 5 x 10(-5) M. The possible involvement of the oxidation of cysteamine and the inhibitory effects of thioacetaldehyde in the cystamine oxidation by amine oxidase is discussed.
Medda
R
R
Institute of Biological Chemistry, University of Cagliari, Italy.
Padiglia
A
A
Lorrai
A
A
De Marco
C
C
Floris
G
G
D006631:Amine Oxidase (Copper-Containing); D003538:Cystamine / Q000378:metabolism; D003543:Cysteamine / Q000378:metabolism*; D007887:Fabaceae / Q000201:enzymology*; D007700:Kinetics; D008956:Models, Chemical; D010084:Oxidation-Reduction; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism; D010946:Plants, Medicinal
D003543:Cysteamine; D006631:Amine Oxidase (Copper-Containing); D000587:Oxidoreductases Acting on CH-NH Group Donors; D003538:Cystamine; D010100:Oxygen