A procedure for analysis of stopped-flow transients for protein-ligand association

A method for extracting kinetic and optical parameters from progress curves for protein-ligand association, obtained by stopped-flow experiments, is described. The method is limited to one-step and two-step association kinetics, but it allows concentration of protein and offset of the signals to be adjustable parameters during an interactive non-linear least-squares fitting procedure. The method is tested on simulated pseudo-experimental data and applied to progress curves obtained in a stopped-flow spectrofluorimeter, for association of the translation initiation factor eIF4E with 7-methyl-GDP, an analog of 5'-end of mRNA.