Abstract
We describe a powerful tool for enzymologists to use for typical non-linear fitting of common equations in enzyme kinetics using the statistical program R. Enzyme kinetics is a powerful tool for understanding enzyme catalysis, regulation, and inhibition but tools to perform the analysis have limitations. Software to perform the necessary nonlinear analysis may be proprietary, expensive or difficult to use, especially for a beginner. The statistical program R is ideally suited to analyzing enzyme kinetic data; it is free in two respects: there is no cost and there is freedom to distribute and modify. It is also robust, powerful and widely used in other fields of biology. In this paper we introduce the program R to enzymologists who want to analyze their data but are unfamiliar with R or similar command line statistical analysis programs. Data are inputted and examples of different non-linear models are fitted. Results are extracted and plots are generated to assist judging the goodness of fit. The instructions will allow users to create their own modifications to adapt the protocol to their own experiments. Because of the use of scripts, a method can be modified and used to analyze different datasets in less than one hour.