Kinase require
Mg++ is the activator of many enzymes requiring ATP. Alkaline phosphatase, hexokinase, fructokinase, phosphofructokinase, adenyl cyclase, cAMP-dependent kinases, etc. need magnesium.Ref: DM Vasudevan, Page no: 420
Mn++
Cu++
Mg++
Inorganic phosphate
Enzymes