Effects of mastoparan B and its analogs on the phospholipase D activity in L1210 cells.
Mastoparan B (MP-B), an amphiphilic alpha-helical peptide isolated from hornet venom, and its Ala-substituted analogs were examined for their effectiveness on phospholipase D (PLD) activity in L1210 cells. PLD activity was determined by measuring phosphatidylethanol produced from [3H]myristate-labelled cells in the presence of ethanol. PLD activity was stimulated by MP-B, 4MP-B (Lys4-->Ala), and 12MP-B (Lys12-->Ala), but not by 3MP-B (Leu3-->Ala) and 9MP-B (Trp9-->Ala). Other MPs including mastoparan 7 also stimulated the PLD activity, but inactive mastoparan 17 did not. The stimulatory effect of various MP analogs could be correlated with their alpha-helical contents. The PLD activity stimulated by MP-B was not affected by G-protein blocking chemicals. The extent of PLD stimulation by various MP-Bs, as well as by digitonin and beta-escin, correlated with the permeability of the membrane to ethidium bromide. These results suggest that the stimulation of PLD activity by MP-B in L1210 cells is probably coupled with membrane perturbation brought about by the peptide.
Department of Chemistry and Center for Molecular Catalysis, Seoul National University, South Korea.
S Y
SY
Lee
N G
NG
Park
M U
MU
Choi
D000818:Animals; D016718:Arachidonic Acid / Q000378:metabolism; D002463:Cell Membrane Permeability / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D019204:GTP-Binding Proteins / Q000187:drug effects; D036341:Intercellular Signaling Peptides and Proteins; D007939:Leukemia L1210 / Q000201:enzymology*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D010739:Phospholipase D / Q000187:drug effects*; D010741:Phospholipases A / Q000187:drug effects; D014862:Wasp Venoms / Q000737:chemistry / Q000494:pharmacology*
D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D014862:Wasp Venoms; C081223:mastoparan B; D016718:Arachidonic Acid; D010741:Phospholipases A; D010739:Phospholipase D; D019204:GTP-Binding Proteins