Amino Acid Dependent Formation of Phosphate Anhydrides in Water Mediated by Carbonyl Sulfide
作者:Luke J. Leman、Leslie E. Orgel、M. Reza Ghadiri
DOI:10.1021/ja056036e
日期:2006.1.1
an efficient condensing agent in the context of phosphate chemistry in aqueous solutions. We report that high-energy aminoacyl-phosphate anhydrides and aminoacyl adenylates are generated in solutions containing aminoacids, COS, and the corresponding phosphate molecule. We further show that the mixed anhydrides of aminoacids and inorganic phosphate are phosphorylating agents, producing pyrophosphate
Adenylation Enzyme Characterization Using γ -18O4-ATP Pyrophosphate Exchange
作者:Vanessa V. Phelan、Yu Du、John A. McLean、Brian O. Bachmann
DOI:10.1016/j.chembiol.2009.04.007
日期:2009.5
We present here a rapid, highly sensitive nonradioactive assay for adenylation enzyme selectivity determination and characterization. This method measures the isotopic back exchange of unlabeled pyrophosphate into gamma-O-18(4)-labeled ATP via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MS), electrospray ionization liquid chromatography MS, or electrospray ionization liquid chromatography-tandem MS and is demonstrated for both nonribosomal (TycA, ValA) and ribosomal synthetases (TrpRS, LysRS) of known specificity. This low-volume (6 mu l) method detects as little as 0.01% (600 fmol) exchange, comparable in sensitivity to previously reported radioactive assays and readily adaptable to kinetics measurements and high throughput analysis of a wide spectrum of synthetases. Finally, a previously uncharacterized A-T didomain from anthramycin biosynthesis in the thermophile S. refuinius was demonstrated to selectively activate 4-methyl-3-hydroxyanthranilic acid at 47 degrees C, providing biochemical evidence for a new aromatic beta-amino acid activating adenylation domain and the first functional analysis of the anthramycin biosynthetic gene cluster.
Berg, Journal of Biological Chemistry, 1958, vol. 233, p. 608
作者:Berg
DOI:——
日期:——
CATALYTIC RNAs WITH AMINOACYLATION ACTIVITY
申请人:The Research Foundation of State University of
New York