Pino R, Mazzetti L, Buffoni F
Department of Pharmacology, University of Florence, Italy.
Mol Genet Metab. 1998 May;64(1):70-5. doi: 10.1006/mgme.1998.2681.
A semicarbazide-sensitive amine oxidase with affinity for benzylamine (Bz.SSAO) was found in the human heart. This enzymatic activity has a K(m) of 278 +/- 35.3 microM and a V(m) of 114.7 +/- 14.7 nmol mg-1 min-1 (mean +/- SE of eight hearts) for benzylamine and is strongly inhibited by 1 mM histamine and by B24, a specific inhibitor of Bz.SSAO. No diamine oxidase activity was found in the human heart. The levels of MAo and B were assayed: MAO A showed a K(m) of 137.1 +/- 16.2 microM and a V(m) of 10.4 +/- 2.5 nmol mg-1 min-1 for serotonin; MAo B had a K(m) of 9.9 +/- 1.6 microM and V(m) of 4.3 +/- 1.1 nmol mg-1 min-1 for beta-phenylethylamine (mean +/- SE of seven hearts). The human heart has high MAO B activity and Bz.SSAO with histaminase activity.
在人心脏中发现了一种对苄胺具有亲和力的氨基脲敏感胺氧化酶（Bz.SSAO）。这种酶活性对苄胺的米氏常数（K(m)）为278±35.3微摩尔，最大反应速度（V(m)）为114.7±14.7纳摩尔·毫克⁻¹·分钟⁻¹（8颗心脏的平均值±标准误），并且受到1毫摩尔组胺和Bz.SSAO的特异性抑制剂B24的强烈抑制。在人心脏中未发现二胺氧化酶活性。测定了单胺氧化酶（MAO）A和B的水平：MAO A对5-羟色胺的K(m)为137.1±16.2微摩尔，V(m)为10.4±2.5纳摩尔·毫克⁻¹·分钟⁻¹；MAO B对β-苯乙胺的K(m)为9.9±1.6微摩尔，V(m)为4.3±1.1纳摩尔·毫克⁻¹·分钟⁻¹（7颗心脏的平均值±标准误）。人心脏具有高MAO B活性和具有组胺酶活性的Bz.SSAO。
