Oh B-C, Choi W-C, Park S, Kim Y-o, Oh T-K
Microbial Genomics Laboratory, Korea Research Institute of Bioscience and Biotechnology, P.O. Box 115, 305-600 Yusong, Taejon, Korea.
Appl Microbiol Biotechnol. 2004 Jan;63(4):362-72. doi: 10.1007/s00253-003-1345-0. Epub 2003 Oct 28.
Phytases are a special class of phosphatase that catalyze the sequential hydrolysis of phytate to less-phosphorylated myo-inositol derivatives and inorganic phosphate. Phytases are added to animal feedstuff to reduce phosphate pollution in the environment, since monogastric animals such as pigs, poultry, and fish are unable to metabolize phytate. Based on biochemical properties and amino acid sequence alignment, phytases can be categorized into two major classes, the histidine acid phytases and the alkaline phytases. The histidine acid phosphatase class shows broad substrate specificity and hydrolyzes metal-free phytate at the acidic pH range and produces myo-inositol monophosphate as the final product. In contrast, the alkaline phytase class exhibits strict substrate specificity for the calcium-phytate complex and produces myo-inositol trisphosphate as the final product. This review describes recent findings that present novel viewpoints concerning the molecular basis of phytase classification.
植酸酶是一类特殊的磷酸酶，可催化植酸依次水解为磷酸化程度较低的肌醇衍生物和无机磷酸盐。由于猪、家禽和鱼类等单胃动物无法代谢植酸，因此在动物饲料中添加植酸酶以减少环境中的磷污染。根据生化特性和氨基酸序列比对，植酸酶可分为两大类，即组氨酸酸性植酸酶和碱性植酸酶。组氨酸酸性磷酸酶类显示出广泛的底物特异性，在酸性pH范围内水解无金属的植酸，并产生肌醇单磷酸作为最终产物。相比之下，碱性植酸酶类对植酸钙复合物表现出严格的底物特异性，并产生肌醇三磷酸作为最终产物。本综述描述了最近的研究发现，这些发现为植酸酶分类的分子基础提供了新的观点。
