The Purification and Properties of Bovine Thrombin

Rapid purification of high purity thrombin and preparation of a novel hemostat for clinical purposes

Thrombin was prepared from crude prothrombin enriched plasma by activation using Russell's viper venom. Prothrombin was prepared by barium sulphate adsorption and elution of prothrombin enriched fraction using high concentrations of sodium citrate. This fraction was directly activated with venom and thrombin was purified by SP Sepharose ion-exchange chromatography and subsequently over Phenyl-sepharose column. This product exhibits a purity of >98% with an activity of at least 6000U/mg or higher. The Thrombin was further used in the preparation of a novel bio-absorbable hemostat using Calcium Alginate fiber sheet which acts as an absorbable hemostat. The present hemostat is highly porous, easy to use and has faster clotting time due to higher solubility of calcium fibers and thereby releasing thrombin.

A rapid simplified purification of bovine thrombin

A rapid simplified method was developed to obtain highly pure bovine thrombin. Prothrombin was directly activated when it was enriched from bovine plasma without prior purification. The activated thrombin was isolated by a single Heparin-Sepharose affinity chromatography step. About 87% of activated thrombin was recovered and the yield was 25.1 mg of thrombin per liter of starting plasma. Specific activity of the final preparation was 4018 NIH units/mg, representing a 402 fold purification over the starting material. Comparative experiments showed that the simplified method was about six times as effective as previous two-step methods.

Rapid sulfopropyl-disk chromatographic purification of bovine and human thrombin

Thrombin, from either a crude commercial preparation (bovine) or a prothrombin activation mixture (human), was purified by sulfopropyl-disk chromatography to homogeneity in a rapid and convenient single-step procedure. The yield of both proteinases was greater than 85%. Purified bovine and human thrombin had sp act of 2500 and 3000 "NIH" units/mg, respectively. Human thrombin was more reactive than bovine thrombin with these active site-directed probes: phenylmethylsulfonyl fluoride, dansyl-Glu-Gly-Arg-chloromethylketone, and human heparin cofactor II. The sulfopropyl-disk chromatographic method is a useful and rapid technique to prepare milligram quantities of highly purified bovine and human thrombin.

Inhibition of esterase and amidase activities of alpha- and beta-thrombin in the presence of antithrombin III and heparin

Inhibition of the esterase and amidase activities of bovine alpha- and beta-thrombin in the presence of antithrombin III and heparin has been studied. It was found that both the esterase and amidase activities of alpha-thrombin were inhibited by antithrombin III and the reactions were accelerated by heparin. The inhibition of amidase and esterase activities of beta-thrombin by antithrombin III has also been demonstrated. Heparin however did not increase the rate of inactivation of the enzyme.

Acrosomal proteinase and proteinase inhibitor of human spermatozoa

The acrosomal proteinase of human spermatozoa was characterized and differs from other human proteinases. The enzyme has optimal activity at pH 8.0, is inactive below pH 5.0 or above pH 10.5, requires calcium for maximum activity, hydrolyzes fibrinogen, gelatin, and benzoylarginine ethyl ester, and is inhibited by various synthetic and natural proteinase inhibitors. The molecular weight was estimated to be 30,000. Human spermatozoa also possess a proteinase inhibitor that is similar to one of the proteinase inhibitors from human seminal plasma.