RESUMEN
Inositol 1,4,5-triphosphate(InsP,) is a second messenger for obilizing intracellular Cal'. It can be dephosphorylated by soluble and particulate forms on InsP, 5-phosphatase, or phosphorylated to produce inositol 1,3,4,5-tetrakisphosphate(InsP,) by InsP, 3-kinase. These enzymes represent possible targets for the regulation of the InsP,AnsP. signal. InsP, 3-kinase which catalyses th ATP-dependent phosphorylation of InsP, was purified from bovine brain tissue. All operation were carried out at 41C. Fresh tissure was homogenized and centrifuged. The supernatant was pooled. Proteins were precipitated from 10% polyethylene glycol, and suspended solution was applied to DEAE cellulose column for chromatography. As the result of above procedure, two isozymes of InsP, 3-kinase, I and U were obtained. Each isozyme was applied to Matriz green gel, Calmodulin-Affigel 15 column and subsequent phenyl-TSK HPLC column. Specific activites(SA) and fold of puriety were observed at each purification step of chromatography. At DEAE cellulose chromatography, SA were 1, 0.6 and 11, 4.8 nM/min/mg, and folds