Enzymatically active peptide from the adenosine diphosphate-ribosylating toxin of Pseudomonas aeruginosa.
A nontoxic peptide (molecular weight, 26,000), which is active in catalyzing the adenosine diphosphate (ADP)-ribosylation of elongation factor 2, has been isolated from the culture supernatant of Pseudomonas aeruginosa strain 103 in stationary phase. Like fragment A from diphtheria toxin, the active peptide catalyzed the hydrolysis of nicotinamide adenine dinucleotide as well as the ADP-ribosylation of elongation factor 2 and showed similarities to fragment A in specific activity, kinetic constants, pH optimum, and ionic sensitivity. These results provide strong evidence for a high degree of homology in the structures of their active sites. That the peptide is not identical to fragment A is shown by the fact that it was not neutralized by fragment A-specific antiserum and was different in amino acid composition and pH and thermal labilities. Although definitive evidence is lacking, there are data suggesting that this peptide is a proteolytic fragment from the ADP-ribosylating toxin (exotoxin A; molecular weight, 66,000) produced by the same strain of P. aeruginosa.
D000247:Adenosine Diphosphate Sugars / Q000378:metabolism; D002474:Cell-Free System; D004167:Diphtheria Toxin / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D009243:NAD / Q000378:metabolism; D010445:Peptide Elongation Factors; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000032:analysis; D012266:Ribose / Q000378:metabolism; D013696:Temperature; D014118:Toxins, Biological / Q000302:isolation & purification / Q000378:metabolism
D000247:Adenosine Diphosphate Sugars; D004167:Diphtheria Toxin; D010445:Peptide Elongation Factors; D010455:Peptides; D014118:Toxins, Biological; D009243:NAD; D012266:Ribose