Evidence for a Transition State Analog, MgADP-Aluminum Fluoride-Acetate, in Acetate Kinase from Methanosarcina thermophila Export

@article{citeulike:5648781, abstract = {Aluminum fluoride has become an important tool for investigating the mechanism of phosphoryl transfer, an essential reaction that controls a host of vital cell functions. Planar AlF3 or AlF[IMG]img001.gif" ALT="<UP><SUB>4</SUB><SUP></SUP></UP>"> molecules are proposed to mimic the phosphoryl group in the catalytic transition state. Acetate kinase catalyzes phosphoryl transfer of the ATP [gamma]-phosphate to acetate. Here we describe the inhibition of acetate kinase from Methanosarcina thermophila by preincubation with MgCl2, ADP, AlCl3, NaF, and acetate. Preincubation with butyrate in place of acetate did not significantly inhibit the enzyme. Several NTPs can substitute for ATP in the reaction, and the corresponding NDPs, in conjunction with MgCl2, AlCl3, NaF, and acetate, inhibit acetate kinase activity. Fluorescence quenching experiments indicated an increase in binding affinity of acetate kinase for MgADP in the presence of AlCl3, NaF, and acetate. These and other characteristics of the inhibition indicate that the transition state analog, MgADP-aluminum fluoride-acetate, forms an abortive complex in the active site. The protection from inhibition by a non-hydrolyzable ATP analog or acetylphosphate, in conjunction with the strict dependence of inhibition on the presence of both ADP and acetate, supports a direct in-line mechanism for acetate kinase. 10.1074/jbc.M105921200}, author = {Miles, Rebecca D. and Gorrell, Andrea and Ferry, James G.}, citeulike-article-id = {5648781}, citeulike-linkout-0 = {http://dx.doi.org/10.1074/jbc.M105921200}, citeulike-linkout-1 = {http://www.jbc.org/cgi/content/abstract/277/25/22547}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/11960978}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=11960978}, day = {14}, doi = {10.1074/jbc.M105921200}, journal = {J. Biol. Chem.}, keywords = {acetate-kinase, adp, aluminum-fluoride}, month = {June}, number = {25}, pages = {22547--22552}, posted-at = {2009-08-26 00:48:15}, priority = {0}, title = {Evidence for a Transition State Analog, MgADP-Aluminum Fluoride-Acetate, in Acetate Kinase from Methanosarcina thermophila}, url = {http://dx.doi.org/10.1074/jbc.M105921200}, volume = {277}, year = {2002} }

TY - JOUR ID - citeulike:5648781 L3 - citeulike-article-id:5648781 N2 - Aluminum fluoride has become an important tool for investigating the mechanism of phosphoryl transfer, an essential reaction that controls a host of vital cell functions. Planar AlF3 or AlF[IMG]img001.gif" ALT="<UP><SUB>4</SUB><SUP></SUP></UP>"> molecules are proposed to mimic the phosphoryl group in the catalytic transition state. Acetate kinase catalyzes phosphoryl transfer of the ATP [gamma]-phosphate to acetate. Here we describe the inhibition of acetate kinase from Methanosarcina thermophila by preincubation with MgCl2, ADP, AlCl3, NaF, and acetate. Preincubation with butyrate in place of acetate did not significantly inhibit the enzyme. Several NTPs can substitute for ATP in the reaction, and the corresponding NDPs, in conjunction with MgCl2, AlCl3, NaF, and acetate, inhibit acetate kinase activity. Fluorescence quenching experiments indicated an increase in binding affinity of acetate kinase for MgADP in the presence of AlCl3, NaF, and acetate. These and other characteristics of the inhibition indicate that the transition state analog, MgADP-aluminum fluoride-acetate, forms an abortive complex in the active site. The protection from inhibition by a non-hydrolyzable ATP analog or acetylphosphate, in conjunction with the strict dependence of inhibition on the presence of both ADP and acetate, supports a direct in-line mechanism for acetate kinase. 10.1074/jbc.M105921200 IS - 25 JF - J. Biol. Chem. EP - 22552 TI - Evidence for a Transition State Analog, MgADP-Aluminum Fluoride-Acetate, in Acetate Kinase from Methanosarcina thermophila VL - 277 SP - 22547 KW - acetate-kinase KW - adp KW - aluminum-fluoride AU - Miles, Rebecca AU - Gorrell, Andrea AU - Ferry, James PY - 2002/06/14/ UR - http://dx.doi.org/10.1074/jbc.M105921200 ER -