Mutenda E K, Sparkes M J, Dixon H B
Department of Biochemistry, University of Cambridge, U.K.
Biochem J. 1995 Sep 15;310 ( Pt 3)(Pt 3):983-8. doi: 10.1042/bj3100983.
The isosteric arsenical analogue of glycerol 3-phosphate, 3,4-dihydroxybutylarsonic acid, is a good substrate for rabbit muscle glycerol-3-phosphate dehydrogenase. Its oxidation is accompanied by release of arsenite. This release seems to be due to a spontaneous elimination of arsenite by 3-oxoalkylarsonic acids, as it is also observed in (1) the oxidation of 3-hydroxypropylarsonic acid by yeast alcohol dehydrogenase, (2) treatment of 3,4-dihydroxybutylarsonic acid with periodate and (3) nonenzymic transamination of the glutamate analogue 2-amino-4-arsonobutyric acid. Enzymic formation of 3-oxoalkylarsonic acids in cells can therefore be lethal, as arsenite is poisonous to most organisms because of its high affinity for dithiols such as dihydrolipoyl groups.
甘油 3 - 磷酸的等排体砷类似物 3,4 - 二羟基丁基胂酸是兔肌肉甘油 - 3 - 磷酸脱氢酶的良好底物。其氧化伴随着亚砷酸盐的释放。这种释放似乎是由于 3 - 氧代烷基胂酸自发消除亚砷酸盐所致，因为在以下情况中也观察到了这种现象：(1) 酵母乙醇脱氢酶氧化 3 - 羟丙基胂酸；(2) 用高碘酸盐处理 3,4 - 二羟基丁基胂酸；(3) 谷氨酸类似物 2 - 氨基 - 4 - 胂基丁酸的非酶转氨作用。因此，细胞中 3 - 氧代烷基胂酸的酶促形成可能是致命的，因为亚砷酸盐对大多数生物体有毒，这是由于它对二硫醇（如二氢硫辛酰基团）具有很高的亲和力。
