An inhibitor of inositol-phospholipid-specific phospholipase C.
Q12713 substance, a cyclic peptide from Actinomadura spp., strongly inhibited the enzyme activity of phosphatidylinositol-4,5-bisphosphate-specific phospholipase C (PIP2-PLC) but scarcely inhibited other phospholipases. Kinetic analysis demonstrated that the inhibition of PIP2-PLC activity was competitive with respect to phosphatidylinositol 4,5-bisphosphate. Calcium and magnesium ions had no significant effect on the inhibitory activity. On the contrary, potassium or rubidium ion was essential for the inhibitory activity. Furthermore, NaF and AlCl3-stimulated increase of phosphoinositides was decreased by Q12713 in the cultured 3T3 cells.
Department of Biochemistry, Meiji College of Pharmacy, Tokyo, Japan.
H
H
Ogawara
K
K
Higashi
S
S
Manita
M
M
Hidaka
H
H
Kato
T
T
Takenawa
D016475:3T3 Cells / Q000187:drug effects; D039903:Actinobacteria / Q000737:chemistry; D000535:Aluminum / Q000494:pharmacology; D000077410:Aluminum Chloride; D017607:Aluminum Compounds; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D008274:Magnesium / Q000494:pharmacology; D051379:Mice; D010456:Peptides, Cyclic / Q000302:isolation & purification / Q000494:pharmacology*; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols / Q000378:metabolism* / Q000494:pharmacology; D054801:Phosphoinositide Phospholipase C; D010727:Phosphoric Diester Hydrolases / Q000187:drug effects* / Q000378:metabolism; D011188:Potassium / Q000494:pharmacology; D012413:Rubidium / Q000494:pharmacology; D012969:Sodium Fluoride / Q000494:pharmacology
D017607:Aluminum Compounds; D002712:Chlorides; D010456:Peptides, Cyclic; D019269:Phosphatidylinositol 4,5-Diphosphate; D010716:Phosphatidylinositols; D000077410:Aluminum Chloride; D012969:Sodium Fluoride; D000535:Aluminum; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D008274:Magnesium; D012413:Rubidium; D011188:Potassium; D002118:Calcium