PubMed HealthSearch

Biomedical subjects

G T James

Publications and source records attributed to G T James.

7 recordsLinked to original sources

Studies in metachromatic leukodystrophy. XIV. Purification and subunit structure of human liver arylsulfatase A.

Arylsulfatase A was purified to apparent homogeneity from normal human livers obtained at autopsy. According to gel electrophoresis in sodium dodecyl sulfate, purified arylsulfatase A consistently contained two subunits of slightly different sizes: approximately 69 000 and 57 000 daltons, but were not present in stoichiometrically equal amounts. Peptide maps of the entire enzyme and of the two individual subunits showed that the two polypeptides share similar if not identical sequences. These observations raise the possibility that the smaller polypeptide might be derived from the larger one. The sensitive peptide mapping procedures employed will make feasible future studies with the abnormal enzyme found in metachromatic leukodystrophy.

Amino Acids

Isolation and characterization of nonhistone chromosomal protein C-14 which stimulates RNA synthesis.

The nonhistone chromatin protein, C-14, was extracted from chromatin of Novikoff hepatoma ascites cells and isolated in high purity as shown by its migration as a single dense spot on two-dimensional polyacrylamide gels. Its mobility on sodium dodecyl sulfate gels is consistent with a molecular weight of approximately 70 000. The amino acid composition shows that protein C-14 has an acidic:basic amino acid ratio of 1.8. Its amino terminal amino acid is lysine. Protein C-14 stimulated the incorporation of [3H]UMP into RNA by approximately 30% when added to naked DNA and homologous RNA polymerase I. A 30% stimulation of [3H]UMP incorporation into RNA was also found when protein C-14 was added to an E. coli RNA polymerase system containing either E. coli or Novikoff hepatoma DNA.

Amino Acid Sequence

The NH2- and COOH-terminal amino acid sequence of nuclear protein A24.

The NH2- and COOH-terminal sequence of nuclear portein A24 has been determined by automatic Edman degradation and carboxypeptidase A and B digestion. Protein A24 is of interest because it is composed in part of histone 2A (Goldknofp, I.L., and Busch, H., (1975) Biochem, Biophys. Res. Commun. 65, 951-960). The sequence of the first 37 NH2-terminal residues is: Met-Gln-Ile-Phe-Val-Lys-Thr-Leu-Thr-Gly-Lys-Thr-Ile-Thr-Leu-Glu-Val-Glu-Pro-Ser-Asp-Thr-Ile-Glu-Asn-Val-Lys-Ala-Lys-Ile-Gln-Asp-Lys-Glu-Gly-Ile-Pro- This sequence is not homologous to any known histone sequence. It contains regions of internal homology (italics). The COOH-terminal amino acid sequence is the same as that of histone 2A, naely: -His-His-Lys-Ala-Lys-Gly-Lys-COOH.

Amino Acid Sequence

Iron removal from transferrin by a cell-free amphibian system.

1. Transferrin-bound iron was released by a cell-free solution prepared from Rana catesbeiana immature erythrocytes, showing that cellular integrity is not necessarily a requirement for this process as previously thought. 2. The biological molecule(s) involved in the removal of iron from transferrin is relatively small.

Animals