title: Heat-modifiable envelope proteins of Bordetella pertussis.
abstract: Several envelope proteins of Bordetella pertussis demonstrated differences in electrophoretic mobility, depending upon solubilization temperature before sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These proteins were exposed on the cell surface as judged by their accessibility to radiolabeling with 125I. Monoclonal antibodies to two of the heat-modifiable proteins (Mrs of 18,000 and 91,000) reacted with intact cells in immunofluorescence microscopy experiments, also indicating surface exposure of these two proteins. Two-dimensional gel electrophoresis revealed that two heat-modifiable proteins (a major protein with an Mr of 38,000 and one with an Mr of 18,000) migrated as higher-Mr moieties when solubilized at low temperatures (25 degrees C). Three proteins (Mrs of 91,000, 32,000, and 30,000) and possibly a fourth (31,000) migrated as lower-Mr species when solubilized at 25 degrees C, as revealed in the two-dimensional gel system; these three proteins were found only in virulent B. pertussis and were not detected in a phase IV avirulent strain nor in a strain modulated to phenotypic avirulence by growth in nicotinic acid. The 38,000 molecular-weight protein (38K protein) and a 25K protein were found to be noncovalently associated with the underlying peptidoglycan. Small amounts of the 91K and 18K proteins were also found associated with peptidoglycan.
mesh_terms: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial / Q000032:analysis; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis*; D001886:Bordetella pertussis / Q000032:analysis* / Q000276:immunology / Q000472:pathogenicity; D004591:Electrophoresis, Polyacrylamide Gel; D006358:Hot Temperature; D007163:Immunosorbent Techniques; D008970:Molecular Weight; D010457:Peptidoglycan / Q000032:analysis; D012995:Solubility
chemical_list: D000911:Antibodies, Monoclonal; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D010457:Peptidoglycan