Abstract |
Adenine phosphoribosyltransferase has been purified to apparent homogeneity from mouse mammary tumor FM3A cells. The purified enzyme, with a specific activity of 20.6 X 10(6) units/ g protein at 30 degrees C, was homogeneous as judged by polyacrylamide gel electrophoresis and Ouchterlony double immunodiffusion analysis. The native enzyme had a molecular weight of 44,000 and a subunit composition of 23,000. Apparent Km values for adenine and 5-phosphoribosyl-1-pyrophosphate (PRib-PP) were 6.6 microM and 1.2 microM, respectively. Free Mg2+ was an essential activator with a half-maximal effect at 0.4 mM. AMP was an inhibitor, competitive with PRib-PP, and the Ki value was estimated to be 24 microM. The enzyme activity was not significantly affected by 2,6-diaminopurine, 4-carbamoylimidazolium 5-olate, 8-azaadenine, and 2-fluoro-6-aminopurine. An antibody against the purified mouse adenine phosphoribosyltransferase was raised in a rabbit. The enzyme derived from either mouse, Chinese hamster, or human cells was completely neutralized and precipitated by this antibody, indicating that these enzymes share a common antigenic determinant.
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Authors | G Okada, I Kaneko, H Koyama |
Journal | Biochimica et biophysica acta
(Biochim Biophys Acta)
Vol. 884
Issue 2
Pg. 304-10
(Nov 19 1986)
ISSN: 0006-3002 [Print] Netherlands |
PMID | 3768421
(Publication Type: Journal Article)
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Chemical References |
- Pentosyltransferases
- Adenine Phosphoribosyltransferase
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Topics |
- Adenine Phosphoribosyltransferase
(isolation & purification)
- Animals
- Catalysis
- Cell Line
- Electrophoresis, Polyacrylamide Gel
- Immunochemistry
- Mammary Neoplasms, Experimental
(enzymology)
- Mice
- Molecular Weight
- Pentosyltransferases
(isolation & purification)
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