In a recent, communication (1) we described the purification and properties of a soluble alanine dehydrogenase isolated from cell-free extracts of the H37Ra strain of Mycobacterium tuberculosis. This enzyme catalyzes the diphosphopyridine nucleotidelinked oxidative deamination of L-alanine to pyruvate. During the study of this enzyme it was observed that Terramycinl inhibits the oxidative react...

Activation-induced deaminase (AID)/APOBEC-family cytosine deaminases, known to function in diverse cellular processes from antibody diversification to mRNA editing, have also been implicated in DNA demethylation, a major process for transcriptional activation. Although oxidation-dependent pathways for demethylation have been described, pathways involving deamination of either 5-methylcytosine (...

Activation-induced cytidine deaminase (AID) initiates somatic hypermutation and class switch recombination in B cells by deaminating C --> U on transcribed DNA. Here we analyze the role of phosphorylation and phosphorylation-null mutants on the biochemical behavior of AID, including enzyme specific activity, processivity, deamination spectra, deamination motif specificity, and transcription-dep...

The autoxidation of nitric oxide (NO.) forms the nitrosating agent N2O3, which can directly damage DNA by deamination of DNA bases following nitrosation of their primary amine functionalities. Within the G:C base pair, deamination results in the formation of xanthine and uracil, respectively. To determine the effect of DNA structure on the deamination of guanine and cytosine, the NO.-induced de...

Chemical interactions between proteins and phenols affect the overall oxidative stability of a given biological system. To investigate the effect of protein-phenol adduct formation on the oxidative stability of β-lactoglobulin (β-LG), the protein was left to react with an equimolar concentration of 4-methylcatechol (4MC), catechin (Cat), or their respective quinone forms, 4-methylbenzoquinone (...

Photo-chemical deamination of cytosine using 3-cyanovinylcarbazole nucleoside (CNVK) mediated photo-cross-linking is a technique for site-directed mutagenesis. Using this technique in vivo requires the elimination of a high-temperature incubation step; instead, incubation should be carried out under physiological conditions. To improve the reactivity of CNVK mediated photo-cross-link induced de...

BACKGROUND Because acute exercise increases systemic catecholamines, we sought to determine whether exercise training would alter daily or exercise-related catecholamine release and inactivation. METHODS AND RESULTS In 24-hour urine collections, catecholamines and metabolites provided indexes of overall oxidative deamination, sulfation, and O-methylation. Plasma catecholamines, the sulfoconju...

Most prokaryotic (cytosine-5)-DNA methyltransferases increase the frequency of deamination at the cytosine targeted for methylation in vitro in the absence of the cofactor S-adenosylmethionine (AdoMet) or the reaction product S-adenosylhomocysteine (AdoHcy). We show here that, under the same in vitro conditions, the prokaryotic methyltransferase, M.MspI (from Moraxella sp.), causes very few cyt...