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J Holtlund

Publications and source records attributed to J Holtlund.

24 records · Page 2Linked to original sources
PubMed1980

Poly(ADP-ribose) polymerase from Ehrlich ascites-tumour cells. Amino acid composition, N-terminal analysis and chemical cleavage of the purified protein.

Poly(ADP-ribose) polymerase was purified from Ehrlich ascites-tumour cells by two novel methods. Analysis for amino acid composition revealed a high percentage of acidic amino acids or their amides, and of basic amino acids. N-Terminal analysis with dansyl chloride revealed no terminal amino acid, indicating a blocked N-terminal amino group. Analysis by gel electrophoresis of protein treated with 3-bromo-3-methyl-2-[(2-nitrophenylthio)-3H-indole, under conditions where selective cleavage of the polypeptide chain at tryptophan residues is obtained, showed six major peptide bands.

Amino Acids↗
PubMed1978

Poly(ADP-ribose) polymerase from Ehrlich ascites tumor cells. Properties of the purified polymerase.

Poly(ADP-ribose) polymerase from Ehrlich ascites tumor cells, partially purified by chromatography on DNA-agarose, was obtained as a more than 80% homogeneous preparation by isoelectric focusing in a sucrose gradient. The polymerase activity was shown to be associated with the major protein in the preparation. Results obtained by electrophoresis in the presence of sodium dodecyl-sulfate indicated that poly(ADP-ribose) polymerase consists of a polypeptide chain with a molecular weight of 130 000. Ultracentrifugation at non-denaturating conditions indicated that the active enzyme may be an oligomeric form of this polypeptide chain. The isoelectric point of the polymerase was 9.40. The effects of various additions to the assay mixture on the synthesis of poly(ADP-ribose) as well as some kinetic data, are given. It is shown that poly(ADP-ribose) is a highly efficient inhibitor of its own synthesis, and results are presented which suggest that the well-known stimulatory effect of DNA on the synthesis is due to reduction of this inhibitory effect of the product.

Animals↗
PubMed1976

Purification of poly(ADP-ribose) polymerase from Ehrlich ascites tumor cells by chromatography on DNA-agarose.

Poly(ADP-ribose) polymerase with a high specific activity was obtained from Ehrlich ascites tumor cells by extraction of nuclei with 175 mM potassium phosphate, followed by chromatography on DNA-agarose. Electrophoretic analysis indicated that the preparation contained two proteins, one of which was shown to catalyze the synthesis of poly(ADP-ribose). As expected from results obtained by other workers, the synthesis was inhibited by nicotinamide and thymidine, and stimulated by DNA. Addition of histones gave inhibition of the synthesis, unless DNA was present in the reaction mixture.

Animals↗