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Biomedical subjects

D J Manners

Publications and source records attributed to D J Manners.

At least 37 records · Page 2Linked to original sources
PubMed1973

Observations of the action of limit dextrinases on amylopectin-like polysaccharides.

The rate of hydrolysis of amylopectin by three different limit dextrinase preparations is only about 15-23% of that of amylopectin beta-limit dextrin under similar conditions. On dilution of the enzymes there was no change in specificity. The factors controlling the specificity of the enzyme and the possible significance in vivo of the results are discussed.

Chromatography, Gel↗
PubMed1973

Studies on beta-glucanases. Some properties of a bacterial endo-beta-(1 leads to 3)-glucanase system.

A commercial enzyme preparation, originally obtained from a Flavobacterium(Cytophaga), was fractionated by continuous electrophoresis, giving a protein fraction which hydrolysed laminarin, carboxymethylpachyman, barley beta-glucan, lichenin and cellodextrin in random fashion. This enzymic activity was not very stable. Ion-exchange chromatography and molecular-sieve chromatography on Bio-Gel P-60 showed that this activity was due to two specific beta-glucanases, an endo-beta-(1-->3)-glucanase and an endo-beta-(1-->4)-glucanase. The two enzymes occur in both high- and low-molecular-weight forms, the latter endo-beta-(1-->3)-glucanase having a molecular weight of about 16000.

Chromatography, Ion Exchange↗
PubMed1973

The structure of a beta-(1 leads to 3)-D-glucan from yeast cell walls.

Yeast glucan as normally prepared by various treatments of yeast (Saccharomyces cerevisiae) cell walls to remove mannan and glycogen is still heterogeneous. The major component (about 85%) is a branched beta-(1-->3)-glucan of high molecular weight (about 240000) containing 3% of beta-(1-->6)-glucosidic interchain linkages. The minor component is a branched beta-(1-->6)-glucan. A comparison of our results with those of other workers suggests that different glucan preparations may differ in the degree of heterogeneity and that the major beta-(1-->3)-glucan component may vary considerably in degree of branching.

Cell Wall↗
PubMed1973

The structure of a beta-(1--6)-D-glucan from yeast cell walls.

By selective enzymolysis, or chemical fractionation, a minor polysaccharide component has been isolated from yeast (Saccharomyces cerevisiae) glucan. This minor component has a degree of polymerization of about 130-140, a highly branched structure, and a high proportion of beta-(1-->6)-glucosidic linkages. The molecules also contain a smaller proportion of beta-(1-->3)-glucosidic linkages that serve mainly as interchain linkages, but some may also be inter-residue linkages.

Cell Wall↗
PubMed1971

Studies on the structure and metabolism of glycogen in some abnormal human infants.

1. The liver and muscle tissues of 14 human anencephalic babies were examined for glycogen content and structure, and for the activities of several glycogen-metabolizing enzymes. 2. In both tissues glycogen content increased with gestation age; the muscle glycogens had a slightly but significantly lower degree of branching than the corresponding liver glycogens. 3. All the expected glycogen-metabolizing enzymes were present; acid maltase activities were higher and phosphoglucomutase activities were lower than the results reported for human adult tissues. Glucose 6-phosphatase activity increased significantly with gestation age.

Anencephaly↗