title: Polylysine-containing peptides, including the carboxyl-terminal segment of the human c-Ki-ras 2 protein, affect the activity of some key membrane enzymes.
abstract: Polylysine-containing peptides are found to affect membrane protein kinases, phosphatidylinositol kinases, and adenylate cyclase. Poly(L-lysine), poly(D-lysine), random copolymers of lysine and serine or lysine and alanine, and poly(L-ornithine) produced large increases in the in vitro phosphorylation of some membrane proteins present in Xenopus laevis oocyte membranes. Poly(L-arginine) did not cause a similar stimulation. In these membranes the phosphorylation of polydisperse protein of approximately 25 kDa was also greatly increased by 1 mM spermine and spermidine, by 10 microM histone H1, or by 200 microM peptide containing the 14-residue sequence at the carboxyl terminus of the human c-Ki-ras 2 gene product, which has eight lysines. Similar specific stimulation of protein phosphorylation was observed with membranes of NG-108-15 nerve cells in culture. Polylysine peptides, including the c-Ki-ras 2 segment, also stimulate the in vitro phosphorylation of membrane inositolphospholipids, to produce mainly phosphatidylinositol 4-phosphate and less phosphatidylinositol 4,5-bisphosphate. Polylysine also alters the activity of oocyte adenylate cyclase, assayed in the presence of either F- or 5'-guanylyl imidodiphosphate.
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology; D005260:Female; D006801:Humans; D007700:Kinetics; D008563:Membrane Lipids / Q000096:biosynthesis; D008565:Membrane Proteins / Q000378:metabolism; D008970:Molecular Weight; D009865:Oocytes / Q000187:drug effects / Q000201:enzymology*; D010455:Peptides / Q000494:pharmacology*; D010743:Phospholipids / Q000096:biosynthesis; D010750:Phosphoproteins / Q000302:isolation & purification; D010766:Phosphorylation; D010770:Phosphotransferases / Q000378:metabolism*; D011107:Polylysine / Q000494:pharmacology*; D011494:Protein Kinases / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000494:pharmacology*; D016283:Proto-Oncogene Proteins p21(ras); D014981:Xenopus
chemical_list: D008563:Membrane Lipids; D008565:Membrane Proteins; D010455:Peptides; D010743:Phospholipids; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D011107:Polylysine; D010770:Phosphotransferases; D011494:Protein Kinases; D019870:1-Phosphatidylinositol 4-Kinase; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras); D000262:Adenylyl Cyclases