title: Further studies on Pseudomonas aeruginosa LasA: analysis of specificity.
abstract: Full elastolytic activity in Pseudomonas aeruginosa is a result of the combined activities of elastase, alkaline proteinase, and the lasA gene product, LasA. The results of this study demonstrate that an active fragment of the LasA protein which is isolated from the culture supernatant fraction is capable of degrading elastin in the absence of elastase, thus showing that LasA is a second elastase produced by this organism. In addition, it is shown that LasA-mediated enhancement of elastolysis results from the separate activities of LasA and elastase upon elastin. The LasA protein does not affect the secretion or activation of a proelastase as previously proposed in other studies. Furthermore, LasA has specific proteolytic capability, as demonstrated by its ability to cleave beta-casein. Preliminary analysis of beta-casein cleavage in the presence of various protease inhibitors suggests that LasA may be classified as a modified serine protease.
authors.affiliation: Department of Microbiology, Ohio State University, Columbus 43210-1292.
authors.forename: J E
authors.initials: JE
authors.lastname: Peters
authors.forename: S J
authors.initials: SJ
authors.lastname: Park
authors.forename: A
authors.initials: A
authors.lastname: Darzins
authors.forename: L C
authors.initials: LC
authors.lastname: Freck
authors.forename: J M
authors.initials: JM
authors.lastname: Saulnier
authors.forename: J M
authors.initials: JM
authors.lastname: Wallach
authors.forename: D R
authors.initials: DR
authors.lastname: Galloway
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism*; D002364:Caseins / Q000378:metabolism; D004549:Elastin / Q000378:metabolism*; D004789:Enzyme Activation; D008666:Metalloendopeptidases; D008969:Molecular Sequence Data; D009154:Mutation; D010196:Pancreatic Elastase / Q000378:metabolism; D011550:Pseudomonas aeruginosa / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D002364:Caseins; D004549:Elastin; D012697:Serine Endopeptidases; D010196:Pancreatic Elastase; D008666:Metalloendopeptidases; C066371:staphylolytic protease