title: Peptitergent PD1 affects the GTPase activity of rat brain cortical membranes.
abstract: Peptitergent PD1 shows complex effects on GTPase activity of rat brain cortical membranes: inhibition in the presence of lower concentrations of GTP and activation at a higher concentration, above 0.5 microM, of GTP. Its effect is dose dependent and is characterized by an EC50 of 1.8 +/- 0.2 microM and a Hill coefficient of 1.6 +/- 0.3, and it increases both Km and Vmax of the GTP hydrolysis. PD1 that was unable to solubilize G-proteins from the membranes probably acts on them by direct binding near the C-terminal alpha-helical region of the Galpha subunit, similarly to mastoparan.
authors.affiliation: Institute of Biochemistry, Medical Faculty, University of Ljubljana, Slovenia.
authors.forename: A
authors.initials: A
authors.lastname: Bavec
authors.forename: A
authors.initials: A
authors.lastname: Juréus
authors.forename: B
authors.initials: B
authors.lastname: Cigić
authors.forename: U
authors.initials: U
authors.lastname: Langel
authors.forename: M
authors.initials: M
authors.lastname: Zorko
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002540:Cerebral Cortex / Q000201:enzymology*; D003902:Detergents / Q000494:pharmacology*; D020558:GTP Phosphohydrolases / Q000187:drug effects*; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000187:drug effects*; D008823:Micelles; D008956:Models, Chemical; D008969:Molecular Sequence Data; D010455:Peptides / Q000494:pharmacology*; D017433:Protein Structure, Secondary; D051381:Rats; D017208:Rats, Wistar; D012995:Solubility; D014862:Wasp Venoms / Q000494:pharmacology
chemical_list: D003902:Detergents; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D008823:Micelles; D010455:Peptides; D014862:Wasp Venoms; C083798:peptitergent PD1; D016244:Guanosine 5'-O-(3-Thiotriphosphate); C037500:mastoparan; D006160:Guanosine Triphosphate; D020558:GTP Phosphohydrolases