guanylyl-imidodiphosphate and barium-chloride

An appropriate mixture of ethylene glycol and BaCl2 enhanced the otherwise very low intrinsic GTPase activity of the elongation factor 2 isolated from the archaeon Sulfolobus solfataricus (SsEF-2). The enzymatic activity became up to 300-fold higher than that of the SsEF-2 GTPase measured in the absence of any stimulator, but remained 20-fold lower than that stimulated by ribosome. The stimulatory effect of ethylene glycol/Ba2+ was attributed to the increased affinity for GTP, probably related to a conformational change occurring in a hydrophobic region near the catalytic site.

Topics: Adenosine Diphosphate Ribose; Alcohols; Barium Compounds; Binding Sites; Cations, Divalent; Chlorides; Ethylene Glycol; Ethylene Glycols; GTP Phosphohydrolase-Linked Elongation Factors; GTP-Binding Proteins; Guanosine Diphosphate; Guanosine Triphosphate; Guanylyl Imidodiphosphate; Hydrogen-Ion Concentration; Hydrolysis; Peptide Elongation Factor 2; Peptide Elongation Factors; Sulfolobus; Temperature