title: Staphylococcal exfoliative toxins cleave alpha- and beta-melanocyte-stimulating hormones.
abstract: The staphylococcal exfoliative toxins (ETs) A and B (ETA and ETB) are 27-kDa exotoxins produced by certain strains of Staphylococcus aureus and are the causative agents of staphylococcal scalded-skin syndrome. The crystal structures of the ETs strongly indicate that the proteins are members of the serine protease family of enzymes, although protease activity until now has not yet been conclusively demonstrated. Here, we show that the peptide beta-melanocyte-stimulating hormone (beta-MSH) is cleaved by ETA and that both ETA and ETB are capable of cleaving alpha-MSH. Both toxins exhibit cleavage at specific glutamic acid residues in MSH peptides. Moreover, biologically inactive mutants of ETA were incapable of cleaving beta-MSH.
authors.affiliation: Department of Microbiology, University of Minnesota Medical School, Minneapolis, Minnesota 55455, USA.
authors.forename: J V
authors.initials: JV
authors.lastname: Rago
authors.forename: G M
authors.initials: GM
authors.lastname: Vath
authors.forename: T J
authors.initials: TJ
authors.lastname: Tripp
authors.forename: G A
authors.initials: GA
authors.lastname: Bohach
authors.forename: D H
authors.initials: DH
authors.lastname: Ohlendorf
authors.forename: P M
authors.initials: PM
authors.lastname: Schlievert
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D004591:Electrophoresis, Polyacrylamide Gel; D004768:Enterotoxins / Q000378:metabolism*; D018698:Glutamic Acid / Q000378:metabolism; D006321:Heart / Q000382:microbiology; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009154:Mutation; D012697:Serine Endopeptidases / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013206:Staphylococcal Scalded Skin Syndrome / Q000378:metabolism; D013210:Staphylococcus / Q000276:immunology; D013696:Temperature; D000521:alpha-MSH / Q000235:genetics / Q000378:metabolism*; D019824:beta-MSH / Q000235:genetics / Q000378:metabolism*
chemical_list: D004768:Enterotoxins; D019824:beta-MSH; C026066:enterotoxin A, Staphylococcal; C031818:enterotoxin B, staphylococcal; D018698:Glutamic Acid; D000521:alpha-MSH; D012697:Serine Endopeptidases