Change in Catalytic Property of Trypsin Immobilized on Support Activated with Glutaraldehyde in Lower Protogenic Solvent

A variety of glutaraldehyde (GA) activated-aminopropyl controlled pore glass supports were prepared in lower protogenic solvents (methanol, ethanol, and n-propanol). When trypsin was used as the ligand, the amount of trypsin immobilized on them decreased in the order of water, methanol, ethanol, and n-propanol; the maximal reduction of 22% was observed in n-propanol versus that in water. The Michaelis constants of the trypsins immobilized on the support activated with GA in alcohols, especially ethanol and propanol, were smaller than that in water, and the minimum Km value of 1.84X10^-1 mM was obtained in propanol (4.29X10^-1 mM in water). During the reaction of GA with 2-aminoethanol, the amount of the aldehyde group from GA being capable of reacting with 2-aminoethanol significantly decreased when the reaction was done in n-propanol (0.18 mmol/assay volume, cf. in water; 035 mmol/assay volume). The gel permeation chromatography (GPC) measurement of the GA complex, glycine-GA-phenetylamine, also revealed the suppression of the GA self-polymerization in the lower protogenic alcohol as a support activating solvent.