Deamination of aliphatic amines of different chain lengths by rat liver monoamine oxidase A and B.
Monoamines with from 1 to 18 straight chain carbon atoms have been analysed as rat liver monoamine oxidase substrates. Methylamine and ethylamine are clearly not substrates of monoamine oxidase (MAO). n-Propylamine, n-butylamine, n-dodecylamine and n-octadecylamine are relatively poor substrates, i.e. with high Km and low Vmax values for the enzyme. n-Pentylamine, n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine and n-decylamine are all very good MAO substrates. All these aliphatic amines are found to be typical type B substrates according to the sensitivities of the enzyme towards the selective MAO-B inhibitor selegiline and the MAO-A inhibitor, clorgyline. The sensitivity towards selegiline with respect to these amines is even higher, i.e. Ki = 1 x 10(-9) M for butylamine, than that of the typical type B substrate beta-phenylethylamine (Ki = 1 x 10(-8) M). The sensitivity towards selegiline decreases slightly with increasing chain length of these aliphatic amines.
Yu
P H
PH
Neuropsychiatric Research Unit, University of Saskatchewan, Saskatoon, Canada.
D000588:Amines / Q000378:metabolism*; D000818:Animals; D003010:Clorgyline / Q000494:pharmacology; D003641:Deamination; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology*; D008995:Monoamine Oxidase / Q000378:metabolism*; D051381:Rats; D012642:Selegiline / Q000494:pharmacology; D013329:Structure-Activity Relationship
D000588:Amines; D012642:Selegiline; D008995:Monoamine Oxidase; D003010:Clorgyline