ORGANIC SOLVENT-RESISTANT PROPERTIES OF PROTEINS ADSORBED ONTO BIOMASS CHARCOAL POWDER

Abstract

We have found out that biomass charcoal powder (BCP), which is prepared from plant biomass wastes by pyrolysis at low temperatures under nitrogen atmosphere, imparts organic solvent resistance to proteins by using BCP as a protein carrier. alpha-Chymotrypsin (alpha-CT), which was used as a model protein, was sufficiently adsorbed onto the surface of BCP. When free alpha-CT and BCP-adsorbed alpha-CT were immersed in acetonitrile containing 5%( v/v) water, they catalyzed the transesterification of N-acetyl-L-tyrosine ethyl ester ( N-Ac-Tyr-OEt) with n-butanol ( BuOH) to produce N-acetyl-L-tyrosine butyl ester ( N-Ac-Tyr-OBu), which did not proceed in an aqueous solution, where alpha-CT worked as a hydrolase. The initial rate of transesterification catalyzed by BCP-adsorbed alpha-CT was strongly dependent upon the kind of BCP, and was about fifty times higher than that catalyzed by free alpha-CT when bamboo charcoal powder was used as a carrier.