STARCH PHOSPHORYLASE INHIBITOR FROM SWEET-POTATO
STARCH PHOSPHORYLASE INHIBITOR FROM SWEET-POTATO
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DOI：
10.1104/pp.80.2.534
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发表时间：
1986-02-01
期刊：
影响因子：
7.4
通讯作者：
SU, JC
中科院分区：
文献类型：
--
作者：
CHANG, TC;SU, JC
从甘薯(Ipomoea Batatas[L.])根中分离纯化出一种淀粉磷酸化酶抑制蛋白。林。CV Tainon 65)。它的相对分子质量为25万，可以由五个相同的亚基组成。缓蚀剂的等电点为4.63。对甘薯酶具有非竞争性抑制作用，其KI值为1.3倍。当以葡萄糖-1-P为可变底物时，底物的摩尔分数为10-6。因为在随机选择的三种植物材料中都发现了兔抗磷酸化酶抑制剂甘薯的交叉反应物质。在马铃薯块茎、菠菜叶和水稻籽粒中，该蛋白的出现似乎在高等植物中普遍存在。通过免疫荧光技术，该抑制物位于淀粉体和细胞壁，在那里也发现了磷酸化酶。这意味着它们可能在体内相互作用，抑制物可能对植物酶起到未知的调节作用。
A protein, starch phosphorylase inhibitor, was purified from the root of sweet potato (Ipomoea batatas [L.] Lam. cv Tainon 65). It had a molecular weight of 250,000 and could be composed of five identical subunits. The isoelectric point of the inhibitor was 4.63. It was a noncompetitive inhibitor toward the sweet potato enzyme with a Ki value of 1.3 .times. 10-6 molar when glucose-1-P was the variable substrate. Because cross-reacting materials of rabbit antiphosphorylase inhibitor of sweet potato were found in three arbitrarily selected plant materials, viz. potato tuber, spinach leaf, and rice grain, the occurrence of this protein seemed universal in higher plants. By an immunofluorescence technique, the inhibitor was located in the amyloplast and cell wall where phosphorylase was also found. This implies that they may interact in vivo, and the inhibitor may play an unknown regulatory role against the plant enzyme.