STUDY ON THE INTERACTION BETWEEN PLASMA-PROTEINS AND POLYION COMPLEX BY CIRCULAR-DICHROISM AND ULTRAVIOLET SPECTROSCOPY

A new method for estimating the amount of adsorbed proteins on polymer surface and the conformational change of the proteins was developed by means of circular dichroism (CD) and ultraviolet spectroscopy (UV). The interaction between plasma proteins and newly synthesized polyion complexes (PIC) was studied conformationally and quantitatively to clarify the effect of electric charge balance of PIC on the adsorption of proteins. A notable difference in charge effect of PIC was observed among protein species; i. e., bovine serum albumin (BSA), γ-globulin (BγG) and fibrinogen (BPF). In the BSA system, few proteins were adsorbed on polyanion-rich PIC and neutral PIC and a large amount of proteins were on polycation-rich PIC. In the BγG system and the BPF systern, however, notable amount of proteins were adsorbed even on polyanion-rich PIC. The conformational change in ad a relationship with the amount of adsorbed BSA. On the other hand the conformational change in β-structure of BγG and especially the change of α-helix content of BPF seemed not to be correlated to the amount of adsorbed proteins. © 1979, The Society of Polymer Science, Japan. All rights reserved.