ium ▁weak ly ▁and ▁non - co oper atively ▁to ▁the ▁third ▁binding ▁site , ▁which ▁has ▁ 5 ▁water ▁mole cules ▁and ▁resid ue ▁G lu 7 0 . ▁After ▁all ▁three ▁mag nes ium ▁ ions ▁have ▁bound , ▁the ▁in os it ol ▁mon oph osph at ase ▁can ▁bind , ▁the ▁neg atively ▁charge ▁ph osph ate ▁group ▁stabil ized ▁by ▁the ▁three ▁posit ively ▁charged ▁mag nes ium ▁ ions . ▁Finally ▁an ▁activ ated ▁water ▁mole c ule ▁acts ▁a ▁nucle oph ile ▁and ▁hydro ly zes ▁the ▁substr ate , ▁giving ▁in os it ol ▁and ▁in organ ic ▁ph osph ate . ▁ ▁Function ▁▁ ▁In os it ol ▁mon oph osph at ase ▁plays ▁an ▁important ▁role ▁in ▁maintain ing ▁int rac ell ular ▁levels ▁of ▁my o - inos it ol , ▁a ▁mole c ule ▁that ▁forms ▁the ▁struct ural ▁basis ▁of ▁several ▁secondary ▁mess engers ▁in ▁e uk ary otic ▁cells . ▁I MP ase ▁de ph osph ory l ates ▁the ▁is om ers ▁of ▁in os it ol ▁mon oph osph ate ▁to ▁produce ▁in os it ol , ▁mostly ▁in ▁the ▁form ▁of ▁the ▁s tere ois omer , ▁my o - inos it ol . ▁In os it ol ▁mon oph osph at ase ▁is ▁able ▁to ▁reg ulate ▁in os it ol ▁home ost asis ▁because ▁it ▁lies ▁at ▁the ▁convergence ▁of ▁two ▁path ways ▁that ▁generate ▁in os it ol : ▁ ▁The ▁ph osph