| Literature DB >> 202956 |
J B Trepel, D M Chuang, N H Neff.
Abstract
Choleragen selectively incorporates 3H from [3H]NAD labeled on the adenosine moiety and not 14C from [14C]NAD labeled on the nicotinamide moiety. This reaction does not require protein in addition to choleragen. Incorporation of isotope does not proceed at 4 degrees, requires dithiothreitol, is stable after extensive washing with cold trichloroacetic acid, and is decreased 80% by boiling in trichloroacetic acid. Studies with the A and B subunits of choleragen show that the A subunit catalyzes ADP-ribosylation and serves as an acceptor protein. The B subunit does not show catalytic or acceptor activity. We conclude that choleragen and its A subunit catalyze the hydrolysis of NAD and the enzymatic transfer of ADP-ribose to the A subunit.Entities:
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Year: 1977 PMID: 202956 PMCID: PMC431754 DOI: 10.1073/pnas.74.12.5440
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN: 0027-8424 Impact factor: 11.205