title: Binding isotherms by continuous-flow dynamic dialysis.
abstract: The classical dynamic dialysis technique for the determination of a protein-ligand binding isotherm has been modified by the introduction of a flow cell in which the dialysate on the sink side of the membrane is continuously eluted with a constant flow of eluting buffer and its ligand concentration measured. This new experimental method is termed continuous-flow dynamic dialysis (CFDD). A transfer function procedure for extracting the binding isotherm from the dialysis data is described. This is a more general technique (requiring only a verifiable assumption of linearity) than that previously used, in which the system was modelled using Fick's first law and which relied on the establishment of quasi-steady state conditions across the membrane. The present analysis uses the Laplace transform to effect deconvolution of the impulse response function of the cell from the dialysis data and, using a Fourier series approach, directly yields numerical data representing the free ligand concentration in equilibrium with the protein-ligand complex. The protein-ligand binding isotherm is obtained in parametric form, with time as the parameter.
authors.affiliation: Leather Industries Research Institute, Rhodes University, P.O. Box 185, Grahamstown 6140, South Africa.
authors.forename: N A
authors.initials: NA
authors.lastname: Sparrow
authors.forename: L
authors.initials: L
authors.lastname: Glasser
authors.forename: D
authors.initials: D
authors.lastname: Glasser
authors.forename: A E
authors.initials: AE
authors.lastname: Russell