Koide Y, Sääf J, Roos S B, Wahlund L O, Wetterberg L
Clin Genet. 1981 May;19(5):400-5. doi: 10.1111/j.1399-0004.1981.tb00734.x.
Monoamine oxidase activity was assayed in platelets from 32 apparently healthy subjects using phenethylamine as substrate and two concentrations of oxygen (0.06 and 0.12 mM). Apparent Km (microM) and Vmax (nmol/mg protein/5 min) values were estimated from double reciprocal plots. The means of the Km and Vmax values were both increased by a factor of about 1.6 when the oxygen concentration was elevated from 0.06 mM (Km = 2.96 and Vmax = 4.47) to 0.12 mM (Km = 4.82 and Vmax = 7.18). The frequency distribution of the Vmax values was not clearly unimodal, especially at the higher oxygen concentration. The Vmax values of the women were significantly higher than those of the men but no sex difference was obtained for the Km values. The overall velocity (v) at 10 microM phenethylamine was highly correlated to the Vmax values both at low and high oxygen concentrations (r = 0.99 and 0.98, respectively).
以苯乙胺为底物，在两种氧浓度（0.06和0.12 mM）下，对32名表面健康受试者的血小板中的单胺氧化酶活性进行了测定。通过双倒数作图法估算表观Km（微摩尔）和Vmax（纳摩尔/毫克蛋白质/5分钟）值。当氧浓度从0.06 mM（Km = 2.96，Vmax = 4.47）升高到0.12 mM（Km = 4.82，Vmax = 7.18）时，Km和Vmax值的均值均增加了约1.6倍。Vmax值的频率分布并非明显单峰，尤其是在较高氧浓度时。女性的Vmax值显著高于男性，但Km值未观察到性别差异。在低氧和高氧浓度下，10微摩尔苯乙胺时的总体速度（v）与Vmax值均高度相关（分别为r = 0.99和0.98）。
