title: Enzyme conformational dynamics during catalysis and in the 'resting state' monitored by hydrogen/deuterium exchange mass spectrometry.
abstract: This work reports the use of electrospray mass spectrometry for studying the conformational dynamics of enzymes by amide hydrogen/deuterium exchange (HDX) measurements. A rapid-mixing quench-flow approach allows comparisons to be made between the HDX kinetics of free enzymes with those under steady-state conditions. Experiments carried out on carboxypeptidase B in the absence of substrate and in the presence of saturating concentrations of hippuryl-Arg result in HDX kinetics that are indistinguishable. This finding implies that the conformational dynamics that mediate HDX are not significantly different in the resting state of the enzyme and during substrate turnover.
authors.affiliation: Department of Chemistry, The University of Western Ontario, London, Ont., Canada N6A 5B7.
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Liu
authors.forename: Lars
authors.initials: L
authors.lastname: Konermann
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000737:chemistry; D043424:Carboxypeptidase B / Q000737:chemistry*; D002384:Catalysis; D002645:Chickens; D003903:Deuterium / Q000737:chemistry*; D041961:Deuterium Exchange Measurement / Q000379:methods; D009113:Muramidase / Q000737:chemistry*; D011487:Protein Conformation; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods; D013552:Swine
chemical_list: C001650:hippuryl-L-arginine; D001120:Arginine; D003903:Deuterium; D009113:Muramidase; D043424:Carboxypeptidase B