Estimation of parameters in double uptake systems

A method is presented for estimating the kinetic parameters describing the cellular uptake of a single molecular species mediated by two independent transport processes. Two cases are considered: first, uptake by two carrier-mediated transport systems, and second, uptake by a single carrier-mediated system and diffusion. Unweighted and weighted least-squares estimations are described; the unweighted estimation is noniterative and provides excellent first approximations for the iterative weighted estimation procedure.