Analysis of myo-inositol hexakisphosphate hydrolysis by Bacillus phytase: indication of a novel reaction mechanism.

摘要: Phytic acid (myo-inositol hexakisphosphate, InsP(6)) hydrolysis by Bacillus phytase (PhyC) was studied. The enzyme hydrolyses only three phosphates from phytic acid. Moreover, the seems to prefer of every second phosphate over that adjacent ones. Furthermore, it is very likely has two alternative pathways for acid, resulting in different myo-inositol trisphosphate end products: Ins(2,4,6)P(3) and Ins(1,3,5)P(3). These results, together with inhibition studies fluoride, vanadate, substrate a analogue, indicate reaction mechanism other phytases. By combining data presented this study (1) structural information obtained crystal structure amyloliquefaciens [Ha, Oh, Shin, Kim, Choi Oh (2000) Nat. Struct. Biol. 7, 147-153], (2) computer-modelling analyses enzyme-substrate complexes, novel mode proposed.