逆ミセル系エステル加水分解反応へのゲストタンパク質の影響

概要

論文の詳細を見る
The catalytic hydrolysis rates of p-nitrophenyl acetate and p-nitrophenyl octanoate in water-in-oil microemulsions of Aerosol-OT (AOT ; sodium bis (2-ethylhexyl) sulfosuccinate) in isooctane were studied. Bovine pancreas α-chymotrypsin, bovine serum albumin (BSA), and palmitic acid-BSA were used as catalysts. The rates of α-chymotrypsin-catalyzed hydrolysis of p-nitrophenyl acetate and p-nitrophenyl octanoate had a bell-shaped patten of dependence on ω_0 (=[H_2O]/[AOT]) with maxima at ω_0=12. In the palmitic acid-BSA-catalyzed reaction, the ω_0-profiles of rate constants for the two esters were similar to those of α-chymotrypsin-catalyzed hydrolysis, but had with maxima at ω_0=15. Comparison of the catalytic activity of α-chymotrypsin with that of palmitic acid-BSA in the microemulsions showed that the water pool radius that gave the highest catalytic activity was almost the same as that of the protein. The ω_0-profile of the rate constant for BSA-catalyzed hydrolysis of p-nitrophenyl acetate was a broad bell-shape. The radius of the water pool that gave the maximum activity near ω_0=20 was larger than that of BSA. The results show that ω_0-dependence of the catalytic activity of solubilized protein is affected by the surface characteristics of the protein.
社団法人日本農芸化学会の論文
1995-03-01