Effect of monovalent cations on bovine alpha- and beta-thrombin: importance of substrate structure.
The relative ability of bovine alpha- and beta-thrombin to hydrolyze selected anilide and ester substrates in presence and absence of monovalent cations has been evaluated. The hydrolysis of both TosGlyProArgpNA and H-D-PhePipArgpNA by either alpha-thrombin or beta-thrombin is more effective in the presence of 0.1 M NaCl than in the presence of 0.1 M KC1. The hydrolysis of BzArgpNA by alpha-thrombin was less effective in the presence of sodium ions than in the presence of potassium ions. The hydrolysis of this latter substrate by beta-thrombin was similar in the presence of either sodium ions or potassium ions. These results suggest that the ionic composition of the solvent affects that catalytic efficiency of alpha-thrombin and beta-thrombin in different ways dependent on the nature of the substrate.
D000818:Animals; D002417:Cattle; D006868:Hydrolysis; D007700:Kinetics; D011188:Potassium / Q000494:pharmacology*; D012964:Sodium / Q000494:pharmacology*; D013379:Substrate Specificity; D013917:Thrombin / Q000494:pharmacology*
D012964:Sodium; D013917:Thrombin; D011188:Potassium