Purification and characterization of a cytosolic phosphoinositide-phospholipase C (gamma 2-type) from human platelets.
A human platelet cytosolic phosphoinositide-specific phospholipase C, one of four PLC activity peaks separated by column chromatographies, designated as cPLC-I, was purified to homogeneity. The cPLC-I exhibited an apparent Mr of 145 kDa by SDS-polyacrylamide gel electrophoresis and was immunologically identified to be PLC-gamma 2. It hydrolyzed PI and PIP2 at optimum pH of 5.5-6.0. Deoxycholate and cholate inhibited the enzyme activity to hydrolyze two substrates. Calcium was required to obtain the maximal activity for PI- and PIP2-hydrolysis at concentration of 10(-3) M and 10(-5) M, respectively. Hg2+ (1 microM) inhibited strongly the enzyme activity.
Banno
Y
Y
Department of Biochemistry, Gifu University School of Medicine, Japan.
Yu
A
A
Nakashima
T
T
Homma
Y
Y
Takenawa
T
T
Nozawa
Y
Y
D001792:Blood Platelets / Q000201:enzymology*; D002845:Chromatography; D002850:Chromatography, Gel; D017886:Durapatite; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006882:Hydroxyapatites; D007700:Kinetics; D008970:Molecular Weight; D010738:Type C Phospholipases / Q000097:blood* / Q000302:isolation & purification
D006882:Hydroxyapatites; D017886:Durapatite; D010738:Type C Phospholipases