title: Identification of two-step chemical mechanisms using small temperature oscillations and a single tagged species.
abstract: In order to identify two-step chemical mechanisms, we propose a method based on a small temperature modulation and on the analysis of the concentration oscillations of a single tagged species involved in the first step. The thermokinetic parameters of the first reaction step are first determined. Then, we build test functions that are constant only if the chemical system actually possesses some assumed two-step mechanism. Next, if the test functions plotted using experimental data are actually even, the mechanism is attributed and the obtained constant values provide the rate constants and enthalpy of reaction of the second step. The advantage of the protocol is to use the first step as a probe reaction to reveal the dynamics of the second step, which can hence be relieved of any tagging. The protocol is anticipated to apply to many mechanisms of biological relevance. As far as ligand binding is considered, our approach can address receptor conformational changes or dimerization as well as competition with or modulation by a second partner. The method can also be used to screen libraries of untagged compounds, relying on a tracer whose concentration can be spectroscopically monitored.
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Laboratoire de Physique Théorique de la Matière Condensée, 4 place Jussieu, case courrier 121, 75252 Paris Cedex 05, France.
authors.forename: F
authors.initials: F
authors.lastname: Closa
authors.affiliation: Laboratoire de Photonique et de Nanostructures, LPN-CNRS, route de Nozay, 91460 Marcoussis, France.
authors.forename: C
authors.initials: C
authors.lastname: Gosse
authors.affiliation: Department of Chemistry, Ecole Normale Supérieure - PSL Research University, 24 rue Lhomond, 75005 Paris, France.
authors.forename: L
authors.initials: L
authors.lastname: Jullien
authors.affiliation: Sorbonne Universités, UPMC Univ. Paris 06, Laboratoire de Physique Théorique de la Matière Condensée, 4 place Jussieu, case courrier 121, 75252 Paris Cedex 05, France.
authors.forename: A
authors.initials: A
authors.lastname: Lemarchand
mesh_terms: D003198:Computer Simulation; D019281:Dimerization; D007700:Kinetics; D008956:Models, Chemical; D010507:Periodicity; D011487:Protein Conformation; D013696:Temperature