guanosine-triphosphate and glycerate-1-3-biphosphate

Intrinsic GTPase activity of GTP-binding proteins plays the vital role in regulating the downstream activation pathway. We examined the GTP and ATP hydrolyzing (NTPase) abilities of various bacterial and human GTP-binding proteins under different metabolic conditions. Two metabolic components, acetate and 3-phosphoglyceric acid (3-PG), have shown significant stimulatory action on NTPase activity of G-protein preparations. Acetyl phosphate and 2,3-bisphosphoglyceric acid (2,3-BPG) blocked these stimulations. From gel filtration analyses, we have determined two fractions containing metabolite-inducible NTPase activities which are independent of GTP-binding protein enzymatic actions. Therefore, one should be cautious when NTPase activity is examined in a buffer containing acetate often used for NTPase assay.

Topics: Acetates; Adenosine Triphosphate; Buffers; Diphosphoglyceric Acids; Escherichia coli; Escherichia coli Proteins; GTP-Binding Proteins; Guanosine Triphosphate; Humans; Organophosphates; Organophosphorus Compounds; Phosphorus Radioisotopes; ras Proteins; RNA-Binding Proteins