PubMed Health⌕ Search

Biomedical subjects

R H Yue

Publications and source records attributed to R H Yue.

16 recordsLinked to original sources
PubMed1980

Separation of heparin into subfractions by DEAE-cellulose chromatography.

Commercial porcine heparin can be separated into three distinct subfractions by using DEAE-cellulose chromatography and a stepped salt gradient. Gram quantities of heparin can be fractionated by this technique. All three heparin subfractions can accelerate the inhibition of thrombin by antithrombin III with different efficiency. The specific activities of the high activity heparin, intermediate activity heparin and low activity heparin are 228 units/mg, 142 units/mg and 95 units/mg, respectively. Both the uronic acid content and the quantity of N-SO4 for all three heparin subfractions have been evaluated. The high activity heparin has the lowest uronic acid and N-SO4 content. The successful separation of commercial heparin into three distinct subfractions by means of ion-exchange chromatography suggests that the net charge on these three heparin components will serve as a model system in the elucidation of the structure and activity relationship to the biological function of heparin.

Animals↗
PubMed1979

Detection and partial purification of a natural heparin inhibitor from hog small intestine.

A natural occurring heparin inhibitor was detected and was partially purified from the mucosa of hog small intestine. The mucosa was homogenized and was extracted overnight in 0.15 M NaCl, 0.01 M imidazole, 0.001 M EDTA, pH 6.5. When the extract was made to 85% saturation in ammonium sulfate, a large quantity of heparin neutralizing activity was detected in the precipitate. Each small intestine contains approximately 35,000 units of heparin neutralizing activity. This heparin inhibitor was further purified by the procedures of zinc sulfate precipitation, ammonium sulfate fractionation, ethanol precipitaiton and heparin-sepharose chromatography. A 37 fold partial purification with 15% overall recovery was achieved to yield heparin inhibitor with specific activity of 50-65 units per mg of protein.

Animals↗
PubMed1978

The binding of calcium ions to bovine factor X by rate dialysis.

The binding of Ca+2 to bovine factor X (molecular weight of 74,000) (Yue und Gertler 1977) was studied by the technique of rate dialysis and with the use of 45Ca+2. The binding data are consistent with a model of sequential mechanism. One mole of Ca+2 binds to the glycoprotein with a dissociation constant of 5.2 X 10(-5) M and additional 39 +/- 4 moles of Ca+2 bind to this zymogen with a dissociation constant of 3.7 X 10(-3) M. The binding of the high affinity Ca+2 causes a functionally significant change in the zymogen, and (calcium) (factor X) complex is the real substrate in the activation process by the protease in Russell's viper venom.

Animals↗
PubMed1977

Isolation of the high molecular form of bovine factor X and some of its physical properties.

A high molecular form of bovine factor X has been isolated from freshly collected bovine blood by BaSO4 absorption, exhaustive washing with 0.001 M BaCl2 and chromatographed on DEAE-cellulose column employing a linear salt gradient. This isolated factor X showed a single protein band on analytical polyacrylamide gel disc electrophoresis. Only one single protein peak was observed in the chromatogram of DEAE-Sephadex A-50 chromatography conducted at 3 degrees C. Sedimentation equilibrium analysis of this bovine factor X revealed no apparent heterogeneity or self association-dissociation phenomena. It yielded a weight-average molecular weight of 74 000 for the native factor X. In the absence of any reducing agent, factor X migrated in dodecyl sulfate gel electrophoresis as a single component with an estimated molecular weight of 74 300. Both dodecyl sulfate gel electrophoresis in the presence of 2-mercaptoethanol and agarose gel chromatography in 6 M guanidinium chloride revealed that this native factor X is composed of two polypeptide chains of molecular weights of 56 000 and 22 100. Factor X can be converted to the enzymatically active factor Xa by Russell's viper venom and in the presence of Ca2+. Factor Xa was purified by DEAE-cellulose chromatography. This Russell's viper venom activated factor Xa also showed a single protein band upon analytical polyacrylamide gel disc electrophoresis. Sedimentation equilibrium analysis of this factor Xa yields a weight-average molecular weight of 59 000 with no apparent heterogeneity or self-association phenomena. In the absence of any reducing agent, factor Xa migrated as a single component in dodecyl sulfate gel electrophoresis with an estimated molecular weight of 58 500. From the results of dodecyl sulfate gel electrophoresis in the presence of 2-mercaptoethanol as well as agarose gel chromatography in 6 M guanidinium chloride, factor Xa is also composed of two polypeptide chains of molecular weights of 36 700 and 22 800. Therefore, the heavy and light chains of both native factor X and factor Xa are linked together by disulfides. Great care was taken in washing the BaSO4 precipitate and it is this effective washing which enabled us to isolate the higher molecular from of bovine factor X.

Animals↗
PubMed1976

Alteration of plasma antithrombin III levels in ischemic heart disease.

The amount of antithrombin III in plasma was determined quantitatively in 218 males between 45-60 years of age. The mean antithrombin III value was found to be low in the group with low risk for ischemic heart disease, intermediate in the group with high risk for ischemic heart disease and highest in the group with acute myocardial infarction. Concomitant study of kaolin-activated partial thromboplastin time revealed a sharp decrease in its mean value in the group with acute myocardial infarction. The high correlation between antithrombin III and kaolin-activated partial thromboplastin time for the entire population suggests that the development of ischemic heart disease is a gradual process and that failure of the damping mechanism results as an acute event. These findings may be useful in the determination of the coagulation state of these patients.

Acute Disease↗