Determination of the Molecular Mass of Silk Fibroin Using the Method of Spectrophotometry

Abstract

The molecular mass of silk fibroin was determined by osmometry, ultracentrifugation, SDS-PAGE methods.One of the most convenient ways to determine the molecular masses of high-molecular compounds is the viscometry method. However, this method is not widely used to determine the molecular mass of fibroin. This is because the coefficients of the Kuhn–Mark–Houwink equation are necessary to determine the molecular mass of fibroin in this way, and there is almost no reliable literature on these coefficients for fibroin. We propose a spectrophotometry method to determine the molecular mass of silk fibroin. Experiments to determine the molecular mass revealed 275 nm wavelength absorbance of aqueous solutions of silk fibroin at different concentrations. A graph of absorbance and concentration dependence was drawn. Using the tangent value of the angle determined for the concentration axis of the straight line obtained in the graph, it was determined that the molecular mass of silk fibroin was 411,7kDa.