Interaction of human serum proteins with synthetic polymers in heterogeneous system

Abstract

AbstractThe interactions of human serum proteins with synthetic macromolecules were studied in heterogeneous solution systems. An alternating copolymer of styrene with maleic anhydride was crosslinked by diamines with different number of methylene groups varying from 2 to 10, and the degree of crosslinking (mole fraction of amide linked units) was changed from 7 to 43% in order to elucidate the effects of pore size, density of ionic site, and flexibility of the macromolecules. The adsorption of serum proteins on the resins was studied with human serum albumin and γ‐globulin as typical proteins in human serum. The resins were dispersed in phosphate buffer solutions, and these were mixed with the phosphate buffer solutions of albumin and/or γ‐globulin. After a suitable period of incubation at 20°C, the mixed solutions were centrifuged. The degree of protein‐adsorption was determined from the remaining amounts of proteins in the supernatant as measured by U.V. spectrometry. It was observed that the adsorption of albumin was influenced by the subtle balance of hydrophobicity and hydrophilicity of the resin. On the other hand, γ‐globulin was adsorbed not only by the hydrophobic resin but also by the hydrophilic (ionic) resin. The resin which was crosslinked to 16% by hexamethylenediamine showed high affinity towards γ‐globulin at pH 7,4. Selective adsorption was also possible: Almost all of the γ‐globulin and only little of the albumin were adsorbed within half an hour at 20°C by the use of this resin.