Inositol 1,4,5-triphosphate phosphatase activity in membranes isolated from amphibian skeletal muscle [corrected].
The hydrolysis of [3H]inositol 1,4,5-trisphosphate by a soluble fraction and by isolated transverse tubule and sarcoplasmic reticulum membranes from frog skeletal muscle was studied. Transverse tubule membranes displayed rates of hydrolysis several-fold higher than those of sacroplasmic reticulum and soluble fraction; Km and Vmax were 25.2 microM and 44.1 nmol/mg/min, respectively. Transverse tubule membranes sequentially hydrolyzed inositol trisphosphate to inositol bisphosphate, inositol 1-phosphate and inositol, indicating that these membranes have inositol bis- and monophosphatases in addition to inositol trisphosphatase.
Sánchez
X
X
Centro de Estudios Cientificos de Santiago, Casilla, Chile.
Carrasco
M A
MA
Vergara
J
J
Hidalgo
C
C
D000818:Animals; D001001:Anura; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D006868:Hydrolysis; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*
D015544:Inositol 1,4,5-Trisphosphate