title: Morphologic features and hydrophobicity of the cell surface of Mycoplasma hyopneumoniae.
abstract: Cell surface hydrophobicity of Mycoplasma hyopneumoniae was evaluated by phase partitioning in a hydrocarbon-aqueous mixture, by hydrophobic interaction chromatography, and by salting out with ammonium sulfate. Results obtained by use of these techniques gave evidence that the cell surface of M hyopneumoniae is weakly hydrophobic, compared with strongly hydrophobic Staphylococcus aureus Cowan I and hydrophilic Klebsiella pneumoniae. After treatment of the organisms with trypsin, M hyopneumoniae became less hydrophobic as measured by hydrophobic interaction chromatography. Significant changes in hydrophobicity were not seen after periodate treatment. Electron microscopy of M hyopneumoniae treated with polycationic ferritin revealed an intermediate, compact, unlabeled layer between the cytoplasmic membrane and an external, heavily labeled layer. Electron microscopy of ferritin-labeled M hyopneumoniae after treatment with trypsin or periodate revealed the intermediate layer to be composed of a trypsin-sensitive protein(s). The outer layer was made of periodate-sensitive carbohydrate(s). Therefore, it appears that proteins in the intermediate layer confer at least part of the total hydrophobicity of the mycoplasmal cell and may contribute to adherence of M hyopneumoniae to target respiratory cells by hydrophobic interactions.
authors.affiliation: Veterinary Medical Research Institute, College of Veterinary Medicine, Iowa State University, Ames 50011.
authors.forename: G C
authors.initials: GC
authors.lastname: Zielinski
authors.forename: R F
authors.initials: RF
authors.lastname: Ross
mesh_terms: D000818:Animals; D005293:Ferritins; D008854:Microscopy, Electron; D008934:Mitogens / Q000494:pharmacology; D009174:Mycoplasma / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D010504:Periodic Acid / Q000494:pharmacology; D013499:Surface Properties; D013552:Swine; D014357:Trypsin / Q000494:pharmacology
chemical_list: D008934:Mitogens; D010504:Periodic Acid; D005293:Ferritins; C009288:metaperiodate; D014357:Trypsin