小麦多酚氧化酶研究进展

Review on Wheat Polyphenol Oxidase (PPO)

综述了小麦多酚氧化酶(PPO)的测定方法、生理功能、酶学特性和基因及其表达。PPO主要位于小麦种(果)皮中,是一类铜结合酶,其活性中心为铜结合区(CuA和CuB),不同植物PPO的铜结合区的氨基酸序列同源性较高。PPO由核基因编码,受多基因控制,有多种同工酶。PPO是导致面制食品的酶促褐变的主要原因,与小麦的抗病性密切相关。

In this article, the research advances on the measuring methods, physiological function, enzymatic properties, and gene expression of polyphenol oxidase (PPO) in wheat (Triticum aestivum L.) were reviewed. In wheat kernel, PPO mainly exists in the pericarp. PPO is a copper-containing metalloprotein. Its active (center) consists of two conserved Cu-binding domains, CuA and CuB. The amino acid composition of PPO is (almost) identical among different plants. PPO is encoded by multiple nucleic genes and has several isoenzymes. PPO is the (primary) causative agent underlying the undesirable enzymatic browning of numerous wheat-based end products. PPO is also closely related to disease resistance in wheat.