ADSORPTION OF ENZYMES AT SILICA-GEL WITH AMPHIPHILIC BLOCK-COPOLYMERS

The amount of adsorbed catalase at silica-gel (Wakogel C-300) having a n average pore size of 7 nm in aqueous solution at pH 7.0 significantl y increased in the presence of the polymer aggregate prepared from an block copolymer (1) consisting of poly[(N-acetylimino)ethylene] and po ly[(N-pentanoylimino)ethylene]. Amounts of adsorbed catalase and horse radish peroxidase (HRP) with an block copolymer (2) containing poly[(N -acetylimino)ethylene] and poly[(N-non-anoylimino)ethylene] at Micro b ead silica gel (MB-800) having an average pore size of 80 nm were meas ured at various pH. In the absence of 2, the affinity of a silica surf ace for catalase in aqueous solutions decreased almost three orders of magnitude when pH in the solutions was raised over pH 7.0. The amount of adsorbed catalase and HRP with 2 was not dependent on pH. The adso rbed amount of catalase on silica surface with 2 in alkaline condition (pH 8.0) was more than 10 times that in the absence of the block copo lymer. The thermal stabilities of adsorbed catalase with and without t he block copolymer (2) were studied in aqueous solution. and the immob ilization of catalase on silica-gel with 2 increased thermal stability .