J J Burchall

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Pertussis toxin is produced by the causative agent of whooping cough, Bordetella pertussis, and is an adenosine diphosphate (ADP)-ribosyltransferase capable of covalently modifying and thereby inactivating many eukaryotic G proteins involved in cellular metabolism. The toxin is a principal determinant of virulence in whooping cough and is a primary(More)
A combination of affinity column chromatography and preparative gel electrophoresis has been used to purify to homogeneity the two isozymes of dihydrofolate reductase from a trimethoprim-resistant strain of Escherichia coli B (RT 500). These enzyme forms are noninterconvertible and are present in crude cell lysates, but other electrophoretic species can be(More)
Burchall, J. J. (University of Illinois, Urbana), R. A. Niederman, and M. J. Wolin. Amino group formation and glutamate synthesis in Streptococcus bovis. J. Bacteriol. 88:1038-1044. 1964.-Extracts of Streptococcus bovis grown on NH(4) (+) as a nitrogen source contain a nicotinamide adenine dinucleotide phosphate (NADP)-linked glutamic dehydrogenase and are(More)
Dihydrofolate reductase has been purified 40-fold to apparent homogeneity from a trimethoprim-resistant strain of Escherichia coli (RT 500) using a procedure that includes methotrexate affinity column chromatography. Determinations of the molecular weight of the enzyme based on its amino acid composition, sedimentation velocity, and sodium dodecyl sulfate(More)
Porcine liver dihydrofolate reductase has been purified 18,000-fold to homogeneity. The properties of the purified enzyme were compared to those of dihydrofolate reductase from L1210 cells, the only mammalian reductase for which complete amino acid sequence data are available. The enzymes are very similar when compared on the basis of mechanism and kinetic(More)