SCHEME 1.
Reaction sequences in SEE. In SEE an enzyme (E) must dissociate from the complex with non-labeled substrate (ES) before it can react with 14C-labeled substrate (14C-S) and release the labeled product (14C-P) to be detected. kon is the association rate constant (liter g−1 s−1); koff is the dissociation rate constant (s−1); kcat is the catalytic constant representing the release of one product molecule (s−1), and Papp is an apparent processivity representing an average number of product molecules released during one processive run. Superscript 14C refers to the parameter for 14C-S.