Why are mammalian alkaline phosphatases much more active than bacterial alkaline phosphatases?
Why are mammalian alkaline phosphatases much more active than bacterial alkaline phosphatases?
复制标题
为什么哺乳动物碱性磷酸酶比细菌碱性磷酸酶活性高得多？
DOI：
10.1111/j.1365-2958.1994.tb01024.x
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发表时间：
1994
影响因子：
3.6
通讯作者：
Kantrowitz,ER
中科院分区：
文献类型：
--
作者：
Murphy,JE;Kantrowitz,ER
哺乳动物碱性磷酸酶的活性比相应的细菌酶高 20-30 倍，尽管它们的氨基酸序列绝对保守 25-30%。在活性位点区域，细菌酶和哺乳动物酶的序列有两个明显的差异，在大肠杆菌酶中，第 153 位和第 328 位分别是天冬氨酸和赖氨酸，但在哺乳动物酶中，在这两个位置都观察到了组氨酸。本文将总结的位点特异性诱变、遗传和 X 射线晶体学数据表明，153 和 328 位的组氨酸取代是细菌和哺乳动物碱性磷酸酶性质差异的主要原因。
Mammalian alkaline phosphatases are 20‐30‐fold more active than the corresponding bacterial enzymes even though their amino acid sequences are 25–30% absolutely conserved. In the active‐site region there are two noticeable differences between the sequences of the bacterial and mammalian enzymes, in theEscherichia colienzyme positions 153 and 328 are Asp and Lys, respectively, but in the mammalian enzymes His is observed at both of these positions. Site‐specific mutagenesis, genetic and X‐ray crystallographic data, which will be summarized here, suggest that the His substitutions at positions 153 and 328 are primarily responsible for the differences in properties between the bacterial and mammalian alkaline phosphatases.