Ray T B, Black C C
J Biol Chem. 1976 Sep 25;251(18):5824-6.
3-Mercaptopicolinic acid specifically inhibits phosphoenolpyruvate carboxykinase in leaves of the C4 plant Panicum maximum. Both the ATP- and ADP-dependent decarboxylation of oxalacetate and the carboxylation activity of phosphoenolpyruvate carboxykinase are inhibited by 3-mercaptopicolinic acid while phosphoenolpyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase are not inhibited. 3-Mercaptopicolinic acid inhibits the fixation of 14CO2 by illuminated P. maximum bundle sheath strands which is dependent upon oxalacetate and ATP but does not affect C3 photosynthesis in bundle sheath strands nor C4 photosynthesis in mesophyll cells. 3-Mercaptopicolinic acid treatment reduced P. maximum leaf photosynthesis 25% while raising the photosynthetic CO2 compensation point from near zero to 18 to 45 mul of CO2/liter of air.
3-巯基吡啶甲酸特异性抑制C4植物大黍叶片中的磷酸烯醇式丙酮酸羧激酶。草酰乙酸的ATP和ADP依赖性脱羧以及磷酸烯醇式丙酮酸羧激酶的羧化活性均受到3-巯基吡啶甲酸的抑制，而磷酸烯醇式丙酮酸羧化酶和核酮糖-1,5-二磷酸羧化酶不受抑制。3-巯基吡啶甲酸抑制光照下大黍维管束鞘细胞对14CO2的固定，这种固定依赖于草酰乙酸和ATP，但不影响维管束鞘细胞中的C3光合作用和叶肉细胞中的C4光合作用。用3-巯基吡啶甲酸处理使大黍叶片光合作用降低25%，同时使光合CO2补偿点从接近零升高到18至45微升CO2/升空气。
