DIFFUSION OF BOVINE SERUM-ALBUMIN IN AMYLOPECTIN GELS MEASURED USING FOURIER-TRANSFORM INFRARED MICROSPECTROSCOPY

A new method of characterizing diffusion in gels using Fourier transfo rm infrared microspectroscopy is described. The system studied was bov ine serum albumin (BSA) diffusing into amylopectin gels. By following the height of the amide peak of the BSA as a function of position alon g the sample, it is possible to build up the concentration profile. Fr om this, the diffusion coefficient can be determined as a function of BSA concentration, amylopectin concentration, and added salt concentra tion. It is shown that charge effects are very important in this syste m. The dependence of the diffusion coefficient on the amylopectin conc entration can be well fitted by a stretched exponential.