ATPase and GTPase activities copurifying with GTP-binding proteins in E. coli.
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.
Department of Biochemistry, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA.
A
A
Sayed
S
S
Matsuyama
K
K
Inoue
J
J
Alsina
F
F
Cai
J
J
Chen
M
M
Inouye
D000085:Acetates / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D002021:Buffers; D004163:Diphosphoglyceric Acids / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D019204:GTP-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006801:Humans; D010755:Organophosphates / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism; D010761:Phosphorus Radioisotopes; D016601:RNA-Binding Proteins; D018631:ras Proteins / Q000302:isolation & purification / Q000378:metabolism
D000085:Acetates; D002021:Buffers; D004163:Diphosphoglyceric Acids; D029968:Escherichia coli Proteins; D010755:Organophosphates; D009943:Organophosphorus Compounds; D010761:Phosphorus Radioisotopes; D016601:RNA-Binding Proteins; C068027:era protein, E coli; C015891:glycerate 1,3-biphosphate; C011632:acetyl phosphate; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D019204:GTP-Binding Proteins; D018631:ras Proteins