title: Radiolabelling of Bordetella pertussis envelope proteins by the 125 I-lactoperoxidase method.
abstract: Bordetella pertussis strain number 18334 was grown in media which yielded cells with either a normal complement of surface antigens (X-model), or cells which were phenotypically altered (C-model). Neither X- nor C-mode bacteria incorporated more than traces of radioactivity when exposed to Na 125 I, lactoperoxidase and a source of H2O2 under conditions which gave substantial labelling of BSA and other soluble proteins. In contrast, envelope preparations were readily labelled. Analysis by sodium dodecyl sulphate-polyacrylamide gel electrophoresis showed that several polypeptides had incorporated 125 I but not in amounts proportional to their abundance in the envelopes. Envelopes from C-mode cells gave a labelling pattern similar to those of X-mode except in one region. Control experiments suggested that the failure of intact cells to become labelled may be due to bacterial inhibition of the reagents.
mesh_terms: D001345:Autoradiography / Q000379:methods; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification*; D001886:Bordetella pertussis / Q000032:analysis*; D002473:Cell Wall / Q000032:analysis; D007457:Iodine Radioisotopes; D007784:Lactoperoxidase; D008970:Molecular Weight; D010455:Peptides / Q000032:analysis
chemical_list: D001426:Bacterial Proteins; D007457:Iodine Radioisotopes; D010455:Peptides; D007784:Lactoperoxidase