HEPARINASE: III. PREPARATION AND PROPERTIES OF THE ENZYME

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Abstract
The extraction of heparinase from beef and rabbit liver was studied. Optimal conditions for precipitation of the enzyme were 33% ammonium sulfate, pH 7.0; 7% ethanol, pH 5.0[long dash]5.5; 40[long dash]70% acetone, pH 8.0; with 0.1% NaCl for ethanol and acetone. A new method of preparation of the enzyme is described, using extraction with 0.15 [image] KC1, precipitation with 33% ammonium sulfate, isoelectric precipitation at 6.0, elution at 37[degree]C, and precipitation at 5.0. This preparation gave a 50% destruction of heparin in 3 hours. The optimum pH was 4.8, substrate concentration, 0.2 mg/ml. Higher concentrations inhibited the enzyme. A linear relation was not obtained between enzyme concentration and velocity of the reaction. The enzyme was inhibited by mercuric chloride, magnesium chloride, lithium chloride, iodoacetate, glutathione, methionine, Versene, and citrate. In liver homogenates, the enzyme activity was associated with all fractions (microsomes, mitochondria, etc.). Active preparations were obtained from liver of man, ox, pig, rabbit, guinea pig, rat,gopher; kidney of ox, pig, rabbit, guinea pig, and rat; muscle of rabbit and guinea pig. No activity was obtained from dog liver, ox testis and thymus, or human placenta. Difficulties in assaying heparinase in tissue extracts are discussed.

This publication has 1 reference indexed in Scilit:

  • HEPARINASE
    Canadian Journal of Medical Sciences, 1952