Kinetic Studies on Pancreatic Lipase Activity in Micellar Systems. II. Effect of Fatty Acid Chain Length of Substrates

概要

論文の詳細を見る
Pancreatic lipase activity toward a series of fatty acid vinyl esters with different chain lengths, solubilized in sodium deoxycholate (NaDC) micelles, was investigated kinetically. The kinetic data could be analyzed on the basis of a fully competitive inhibition mechanism, where substratefree NaDC micelles act as a competitive inhibitor. The values of inhibition constant (K_4), which is the dissociation constant of lipase-NaDC micelle complex, obtained from the reaction of each substrate were in reasonable agreement with one another. On the other hand, the maximum velocity (V) and the Michaelis constant (K_m) increased with decrease in the fatty acid chain length (C_<14>≃C_<12><C_<10><C_8). The V/K_m values indicate that vinyl dodecanoate and tetradecanoate are better substrates than vinyl decanoate and octanoate in this micellar system. The K_m/K_4 values suggest that the lipase-substrate-solubilizing NaDC micelle complex is less stable than the lipase-substrate-free NaDC micelle complex. The changes in the V and K_m values with chain length were ascribed to the difference in the interaction between the substrate molecule and NaDC micelles.
公益社団法人日本薬学会の論文
1983-12-25