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Biomedical subjects

J Williams

Publications and source records attributed to J Williams.

At least 1,189 records · Page 66Linked to original sources
PubMed1968

A comparison of glycopeptides from the ovotransferrin and serum transferrin of the hen.

1. Glycopeptides were prepared from proteolytic digests of ovotransferrin and serum transferrin of the hen. The carbohydrate compositions and amino acid sequences of the peptides were studied. 2. The bulk of the carbohydrate of ovotransferrin is present as a single oligosaccharide composed of 4 residues of mannose and 8 residues of N-acetylglucosamine. Transferrin has most of its carbohydrate in a single unit composed of 2 residues of mannose, 2 residues of galactose, 3 residues of N-acetylglucosamine and either 1 or 2 residues of sialic acid. 3. The amino acid sequences of the glycopeptides carrying these different oligosaccharides are the same in ovotransferrin and serum transferrin, showing that the carbohydrate groups are attached to the same site on the protein molecule.

Amino Acid Sequence↗
PubMed1968

The isoelectric fractionation of hen's-egg ovotransferrin.

1. Hen ovotransferrin was examined by isoelectric fractionation. 2. The major component observed in starch-gel electrophoresis can be isolated from the minor component. 3. When non-saturating amounts of iron are added to ovotransferrin, isoelectric fractionation demonstrates the existence of three molecular species corresponding to the metal-free protein, the one-iron-atom-protein complex and the two-iron-atoms-protein complex. 4. Isoelectric fractionation of human serum labelled with (59)Fe suggests that the transferrin of normal human serum also exists as metal-free protein, the one-iron-atom-protein complex and the two-iron-atoms-protein complex. 5. It is concluded that the binding constants for the first and second iron atoms are similar.

Amino Acids↗