多聚磷酸相关蛋白结构及生物学功能

多聚磷酸（polyphosphate，polyP）是由几个到数百个磷酸基通过高能磷酸酐键连接而成的链状多聚体，存在于所有细胞生物中.多聚磷酸相关蛋白包括多聚磷酸相关酶和多聚磷酸结合蛋白.多聚磷酸相关酶如多聚磷酸激酶（polyphosphate kinase，PPK）催化polyPn生成polyPn+1的可逆反应；外切聚磷酸酶（exopolyphosphatase，PPX）、内切聚磷酸酶（endopolyphosphatase，PPN）能将polyP水解成磷酸残基；多聚磷酸依赖的激酶将polyP的磷转移到生物小分子上，如葡萄糖和烟酰胺腺嘌呤二核苷酸（nicotinamide adenine dinucleotide，NAD）,使其分别磷酸化为6 磷酸葡萄糖和烟酰胺腺嘌呤二核苷酸磷酸（nicotinamide adenine dinucleotide phosphate，NADP）.多聚磷酸结合蛋白可与多聚磷酸结合，发挥各种生物学功能.本文将简要介绍多聚磷酸相关蛋白的结构与主要生物学功能，以阐述多聚磷酸参与的细胞内生化过程.

The Structure and Biological Function of Polyphosphate related Proteins

Polyphosphate (polyP), comprising several to hundreds of phosphate (Pi) residues linked by phosphoanhydride bonds, the same type of bond that links the phosphates in ATP, has been found in every cell examined, from bacteria to mammals. PolyP-related proteins include polyP-related enzymes and polyP-binding proteins. PolyP-related enzymes, such as polyP kinase (PPK) which catalyzes the reversible synthesis of polyP from the terminal phosphate of ATP, and exopolyphosphatase (PPX) and endopolyphosphatase (PPN) which hydrolyze polyP to shorter chains or Pi, have been identified in a variety of micro-organisms. PolyP-dependent kinases that transfer a phosphate from polyP to small molecules such as glucose and nicotinamide adenine dinucleotide (NAD) have also been described. PolyP-binding proteins bind polyP and exert many physiological effects. We speculate on the roles of polyP in biological process are to understand the structures and biological functions of polyP-related proteins.