Substrate selectivity of monoamine oxidase A, monoamine oxidase B, diamine oxidase, and semicarbazide-sensitive amine oxidase in COS-1 expression systems.
The substrate selectivity of monoamine oxidase A (MAO-A), monoamine oxidase B (MAO-B), diamine oxidase (DAO), and semicarbazide-sensitive amine oxidase (SSAO) was investigated in the absence of chemical inhibitors using the COS-1 cells expressed with respective amine oxidase. Serotonin (5-hydroxytryptamine), 1-methylhistamine, and histamine were preferentially oxidized by MAO-A, SSAO, and DAO, respectively, at a low substrate concentration. In contrast, benzylamine, tyramine, and beta-phenylethylamine served as substrates for all of MAO-A, MAO-B, and SSAO. Each amine oxidase showed broad substrate selectivity at a high substrate concentration. The cross-inhibition was remarkable in MAO-A and MAO-B, especially in MAO-A, but not in SSAO and DAO. A study of the substrate selectivity of amine oxidases should include consideration of the effects of substrate concentration and specific chemical inhibitors.
Ochiai
Yoshinori
Y
Department of Drug Metabolism and Pharmacokinetics, Tohoku Pharmaceutical University, Sendai, Japan.
Itoh
Kunio
K
Sakurai
Eiichi
E
Adachi
Mayuko
M
Tanaka
Yorihisa
Y
D006631:Amine Oxidase (Copper-Containing) / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002522:Chlorocebus aethiops; D017931:DNA Primers; D008995:Monoamine Oxidase / Q000378:metabolism*; D013379:Substrate Specificity
D017931:DNA Primers; D006631:Amine Oxidase (Copper-Containing); D008995:Monoamine Oxidase