A peptide corresponding to a potential polyphosphoinositide binding site of phospholipase C-beta 2 enhances its catalytic activity.
A peptide corresponding to a basic consensus amino acid motif present in both actin-binding proteins and phosphoinositide-specific phospholipases C was synthesized and its effect on the activity of a recombinant phospholipase C-beta 2 (PLC beta 2) expressed in baculovirus-infected insect cells was studied. The peptide markedly and specifically stimulated the activity of the enzyme. This stimulatory effect required a particular primary and/or secondary structure of the peptide and occurred without lowering the affinity of the enzyme for Ca2+. The function of the PLC beta 2 segment corresponding to the peptide might be to bind and offer the substrate to the catalytic domain of this enzyme in a more favorable configuration or, alternatively, to interact with a hypothetical inhibitory constraint.
German Cancer Research Center, Heidelberg.
A P
AP
Simões
P
P
Schnabel
R
R
Pipkorn
M
M
Camps
P
P
Gierschik
D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D004789:Enzyme Activation; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D009036:Moths; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology; D010716:Phosphatidylinositols / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D010738:Type C Phospholipases / Q000378:metabolism*
D010455:Peptides; D010716:Phosphatidylinositols; D011994:Recombinant Proteins; D010738:Type C Phospholipases; D002118:Calcium