Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.4.2.30 (PARP)
 13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pertussis toxin (PT), an oligomeric exotoxin of Bordetella pertussis containing five dissimilar subunits, is considered to be an essential immunogen in acellular and component pertussis vaccines against whooping cough. A rapid single-step procedure for isolating PT subunits was developed using reverse-phase high-performance liquid chromatography. Recoveries of individual subunits were 75% (S1), 70% (S2), greater than 90% (S3), greater than 90% (S4), and 50% (S5), as judged by SDS-PAGE and amino acid analysis. Lyophilized subunits were solubilized in urea followed by step-wise dialysis to remove the urea. All subunits were inactive in histamine sensitization, lymphocytosis, and hemagglutination assays. However, purified S1 retained residual NAD-glycohydrolase and ADP-ribosyltransferase activity. A partially active holotoxin could be generated by mixing the five individual subunits. All subunits were immunogenic in rabbits and mice. Monospecific antisera raised in both animal species were able to neutralize the PT-mediated clustering of Chinese hamster ovary cells, but active immunization of mice with single subunits failed to protect them in the intracerebral challenge assay. These subunit preparations therefore retained neutralizing determinants, but did not contain protective epitopes.
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PMID:Purification and immunological characterization of HPLC-purified pertussis toxin subunits. 165 40

Chemical modification of amino groups in the molecule of islet-activating protein (IAP), pertussis toxin, resulted in differential modification of biological activities of the toxin estimated in vivo with rats. Acetamidination of epsilon-amino groups of 50% (or more) of lysine residues in the IAP molecule totally abolished the lymphocytosis-promoting activity, but exerted no effects on the epinephrine-hyperglycemia inhibitory activity, of the toxin. Both activities were abolished by acylation of 50% or more of the amino groups probably due to the destruction of the toxin's quarternary structure. In contrast, the subunit assembly of IAP was maintained after exhaustive acetamidination of its lysine residues. The ADP-ribosyltransferase (or NAD-glycohydrolase) activity of the A-promoter (the biggest subunit) of IAP, which is responsible for the principal action of the toxin, enhancing insulin secretory responses and thereby inhibiting epinephrine hyperglycemia, was not affected by acetamindination of lysine residues. Thus, the A-protomer moiety of IAP is not directly involved in, but the amino groups of lysine residues in other subunits are selectively essential for, the development of the toxin-induced lymphocytosis.
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PMID:Chemical modification of islet-activating protein, pertussis toxin. Essential role of free amino groups in its lymphocytosis-promoting activity. 654 Oct 59