title: GTP-binding proteins in etiolated epicotyls of Pisum sativum (Alaska) seedlings.
abstract: Seven fractions of GTP-binding proteins separated by gel filtration of an extract of epicotyls of Pisum sativum seedlings were partially characterized. Seven fractions of GTP-binding proteins tentatively designated GP1 to GP7 had the capacity to be ADP-ribosylated by pertussis toxin. Pooled fractions of GP2 to GP7 showed Km values 2, 20, 50, 10, 3 and 1 nM, respectively. The binding of [35S]GTP gamma S to GTP-binding proteins was prevented competitively in the presence of 0.1 mM GTP and also prevented in the presence of 0.1 mM ATP. Binding of [35S]GTP gamma S to the proteins produced a decrease in their molecular weights.
mesh_terms: D000246:Adenosine Diphosphate Ribose / Q000378:metabolism; D002850:Chromatography, Gel; D007887:Fabaceae; D019204:GTP-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D007700:Kinetics; D037342:Pertussis Toxin; D010944:Plants / Q000378:metabolism*; D010946:Plants, Medicinal; D011485:Protein Binding; D013873:Thionucleotides / Q000378:metabolism; D010566:Virulence Factors, Bordetella / Q000378:metabolism
chemical_list: D013873:Thionucleotides; D010566:Virulence Factors, Bordetella; D000246:Adenosine Diphosphate Ribose; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins