Kinetics and mechanism of the hydrolysis of esters of hydroxymethylphosphonic and hydroxymethylethylphosphinic acids

1985 ◽  
Vol 34 (9) ◽  
pp. 1978-1979
Author(s):  
V. E. Bel'skii ◽  
A. M. Zotova ◽  
L. A. Kudryavtseva ◽  
B. E. Ivanov
Keyword(s):  
Kinetics And Mechanism ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

The Effects of Amines on the Esterase Activities of Thrombin and Thrombokinase and on Several Clotting Tests

1974 ◽  
Vol 31 (02) ◽  
pp. 309-318
Author(s):  
Phyllis S Roberts ◽  
Raphael M Ottenbrite ◽  
Patricia B Fleming ◽  
James Wigand
Keyword(s):  
Choline Chloride ◽  
Polymerization Process ◽  
Ammonium Bromide ◽  
Bovine Thrombin ◽  
One Stage ◽  
Human Proteins ◽  
Rate Of Hydrolysis ◽  
The One ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

Summary1. Choline chloride, 0.1 M (in 0.25 M Tris. HCl buffer, pH 7.4 or 8.0, 37°), doubles the rate of hydrolysis of TAME by bovine thrombokinase but has no effect on the hydrolysis of this ester by either human or bovine thrombin. Only when 1.0 M or more choline chloride is present is the hydrolysis of BAME by thrombokinase or thrombin weakly inhibited. Evidence is presented that shows that these effects are due to the quaternary amine group.2. Tetramethyl ammonium bromide or chloride has about the same effects on the hydrolysis of esters by these enzymes as does choline chloride but tetra-ethyl, -n.propyl and -n.butyl ammonium bromides (0.1 M) are stronger accelerators of the thrombokinase-TAME reaction and they also accelerate, but to a lesser degree, the thrombin-TAME reaction. In addition, they inhibit the hydrolysis of BAME by both enzymes. Their effects on these reactions, however, do not follow any regular order. The tetraethyl compound is the strongest accelerator of the thrombokinase-TAME reaction but the tetra-ethyl and -butyl compounds are the strongest accelerators of the thrombin-TAME reaction. The ethyl and propyl compounds are the best (although weak) inhibitors of the thrombokinase-BAME and the propyl compound of the thrombin-BAME reactions.3. Tetra-methyl, -ethyl, -n.propyl and -n.butyl ammonium bromides (0.01 M) inhibit the clotting of fibrinogen by thrombin (bovine and human proteins) at pH 7.4, imidazole or pH 6.1, phosphate buffers and they also inhibit, but to a lesser degree, a modified one-stage prothrombin test. In all cases the inhibition increases regularly as the size of the alkyl group increases from methyl to butyl. Only the ethyl com pound (0.025 M but not 0.01 M), however, significantly inhibits the polymerization of bovine fibrin monomers. It was concluded that inhibition of the fibrinogen-thrombin and the one-stage tests by the quaternary amines is not due to any effect of the com pounds on the polymerization process but probably due to inhibition of thrombin’s action on fibrinogen by the quaternary amines.

ChemInform Abstract: KINETICS AND MECHANISM OF THE HYDROLYSIS OF IMIDOYL HALIDES

1976 ◽  
Vol 7 (40) ◽  
pp. no-no
Author(s):  
TAE-RIN KIM ◽  
JIN-HEE KIM ◽  
BYUNG-DOO CHANG ◽  
KWANG-IL LEE ◽  
UNG-CHO KIM
Keyword(s):  
Kinetics And Mechanism ◽  
Hydrolysis Of

scholarly journals The α-Chymotrypsin-catalyzed Hydrolysis of Esters of α-Amino Acids

1972 ◽  
Vol 247 (18) ◽  
pp. 5746-5752
Author(s):  
Ferenc J. Kézdy ◽  
Satya P. Jindal ◽  
Myron L. Bender
Keyword(s):  
Amino Acids ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of

Kinetics and mechanism of the aquation and base hydrolysis of the nitratopentaamminecobalt(III) ion and related complexes

1969 ◽  
Vol 8 (11) ◽  
pp. 2504-2508 ◽  
Author(s):  
William Edward Jones ◽  
Robert B. Jordan ◽  
T. W. Swaddle
Keyword(s):  
Kinetics And Mechanism ◽  
Base Hydrolysis ◽  
Hydrolysis Of
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