Glycerophosphoinositol inositolphosphodiesterase
In enzymology, a glycerophosphoinositol inositolphosphodiesterase () is an enzyme that catalyzes the chemical reaction Thus, the two substrates of this enzyme are 1-(sn-glycero-3-phospho)-1D-myo-inositol and HO, whereas its two products are glycerol and 1D-myo-inositol 1-phosphate. This enzyme belongs to the family of hydrolases, specifically those acting on phosphoric diester bonds. The systematic name of this enzyme class is 1-(sn-glycero-3-phospho)-1D-myo-inositol inositolphosphohydrolase. Other names in common use include 1,2-cyclic-inositol-phosphate phosphodiesterase, D-myo-inositol 1:2-cyclic phosphate 2-phosphohydrolase, D-inositol 1,2-cyclic phosphate 2-phosphohydrolase, D-myo-inositol  1,2-cyclic phosphate 2-phosphohydrolase, 1-D-myo-inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase, and inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase. This enzyme 1-D-myo-inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase, was reported to be identical to annexin III [Ross et al., Science, 248: 605-607, 1990]. Sekar et al. [J Biol. Chem. 271: 8295-8299, 1996] clearly demonstrated the dissociation of 1-D-myo-inositol-1,2-cyclic-phosphate 2-inositolphosphohydrolase activity from annexin III. Perron et al. [J. Biol. Chem. 272:11321-11326, 1997] confirmed based on structural studies that annexin III did not possess an enzymatic activity. While physiological significance of this  enzymatic activity is still not clear, Sekar et al. [Biochem. Mol. Med. 61:95-100, 1007] reported over 10-fold increased release of this enzymatic activity in several patients admitted to the hospital's intensive care unit.