MacDonald M J
Biochim Biophys Acta. 1978 Sep 11;526(1):293-8. doi: 10.1016/0005-2744(78)90314-5.
Liver cytosolic or mitochondrial fractions of five species were incubated with 30 micrometer Fe2+ or with 100 micrometer Mn2+ prior to assaying for phosphoenolpyruvate carboxykinase (GTP:oxaloacetate carboxy-lyase (transphosphorylating), EC 4.1.1.32) acticity in the presence of 3-mercaptopicolinate. Only the cytosolic carboxykinases were activated 3--4-fold by Fe2+ or Mn2+. Fe2+ enhanced the inhibitory potency of 3-mercaptopicolinate 10--50-fold against the cytosolic and the mitochondrial carboxykinases, but Mn2+ was ineffective. Mn2+ interfered with Fe2+ -enhancement of inhibition by 3-mercaptopicolinate in a manner competitive with Fe2+. It is hypothesized that Fe2+ and 3-mercaptopicolinate form a coordination complex that inhibits the carboxylkinases and that 3-mercaptopicolinate does not blind to a carboxykinase containing Mn2+.
在存在3-巯基吡啶甲酸盐的情况下测定磷酸烯醇丙酮酸羧激酶（GTP：草酰乙酸羧基裂解酶（转磷酸化），EC 4.1.1.32）活性之前，将五个物种的肝脏胞质或线粒体部分与30微摩尔Fe2+或100微摩尔Mn2+一起孵育。只有胞质羧激酶被Fe2+或Mn2+激活了3至4倍。Fe2+使3-巯基吡啶甲酸盐对胞质和线粒体羧激酶的抑制效力增强了10至50倍，但Mn2+无效。Mn2 +以与Fe2+竞争的方式干扰3-巯基吡啶甲酸盐对Fe2+抑制作用的增强。据推测，Fe²⁺和3-巯基吡啶甲酸盐形成一种抑制羧激酶的配位络合物，并且3-巯基吡啶甲酸盐不会与含有Mn2+的羧激酶结合。
