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Biomedical subjects

F B Williamson

Publications and source records attributed to F B Williamson.

At least 91 records · Page 5Linked to original sources
PubMed1980

Evidence for antithrombin III involvement in the anticoagulant activity of cellulose sulphate.

1 Cellulose sulphate, like heparin, prolonged the clotting time in partial thromboplastin time (PTT) assays, inhibited the amidolytic activity of thrombin, was without effect on amidolysis catalysed by activated coagulation factor X(Xa), and potentiated the inhibition of both thrombin and Xa by antithrombin III (AT). 2 The anticoagulant activity of cellulose sulphate in PTT assays was, like that of heparin and heparin sulphate, but unlike that of dermatan sulphate, reduced by prior incubation of plasma with antiserum specific for AT. 3 These results, which suggest that the anticoagulant activity of cellulose sulphate is at least partially mediated through AT, are discussed in terms of the structural features of polysaccharides required for AT activation.

Adolescent↗
PubMed1979

kappa-Carrageenase from Pseudomonas carrageenovora.

A kappa-carrageenase was isolated from the cell-free medium of cultured Pseudomonas carrageenovora. From dodecylsulphate/polyacrylamide gel electrophoresis, a single protein (identified as the kappa-carrageenase) was detected in the medium. Activity against nominal carrageenan types and inspection of the products indicate the enzyme to be a kappa-carrageenase. Purification is described here by ammonium sulphate precipitation and subsequent CM-Sepharose CL-6B ion-exchange chromatography. Molecular weight was estimated as 35,000 by dodecylsulphate/polyacrylamide gel electrophoresis. Products of degradation were analysed by gel filtration, spectrophotometric assays and 13C nuclear magnetic resonance. These results are consistent with the product of limit digest being neocarrabiose 4-O-sulphate.

Carrageenan↗
PubMed1979

Glycosulphatase from Pseudomonas carrageenovora. Purification and some properties.

A glycosulphatase present in the soluble fraction of disrupted Pseudomonas carrageenovora has been purified 500-fold by gel filtration on Sephacryl S-200 and ion-exchange chromatography on DEAE-Sepharose CL-6B. By dodecylsulphate/polyacrylamide gel electrophoresis the enzyme is practically homogeneous and has a molecular weight of 55 000. Conditions of optimal sodium chloride concentration and pH at 25 degrees C were 0.25--0.50 mol dm-3 and pH 7.0 respectively. The purified enzyme was inhibited by inorganic phosphate. Preparation is described of neocarrabiose 4-O-[35S]sulphate and neocarratetraose 4-O-[35S]sulphate from labelled Chondrus crispus. The purified glycosulphatase is active against both these substrates although only one of the two sulphate esters in the tetrasaccharide is hydrolysed. Analysis of the reaction products was by gel filtration, electrophoresis and 13C nuclear magnetic resonance spectroscopy. The results are consistent with the products of desulphation being respectively neocarrabiose and neocarratetraose 4-O-monosulphate with the sulphate ester proximal to the reducing end [3,6-anhydro-alpha-D-galactopyranosyl-(1 leads to 3)-beta-D-galactopyranosyl-(1 leads to 4)-3,6-anhydro-alpha-D-galactopyranosyl-(1 leads to 3)-D-galactose 4-O-sulphate].

Glycosides↗