title: Proteins IA and IB exhibit different surface exposures and orientations in the outer membranes of Neisseria gonorrhoeae.
abstract: Exposure of whole gonococci to proteinase K resulted in cleavage of protein I (P.I) of the organism in situ. P.I subunits in the P.IB group were cleaved into two membrane-associated fragments, whereas P.IA subunits were cleaved by proteinase K to yield a single membrane-associated fragment slightly smaller in apparent size than the intact P.IA subunit. These data suggest that P.IA and P.IB subunits are quite different in their surface exposures and orientations in the gonococcal outer membrane; P.IB subunits likely have both termini buried in the membrane, whereas P.IA subunits have one of their termini exposed on the surface of the organism.
mesh_terms: D001425:Bacterial Outer Membrane Proteins; D002462:Cell Membrane / Q000032:analysis; D002918:Chymotrypsin / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019286:Endopeptidase K; D010450:Endopeptidases / Q000378:metabolism; D046911:Macromolecular Substances; D008565:Membrane Proteins / Q000032:analysis*; D008970:Molecular Weight; D009344:Neisseria gonorrhoeae / Q000032:analysis*; D010446:Peptide Fragments / Q000032:analysis
chemical_list: D001425:Bacterial Outer Membrane Proteins; D046911:Macromolecular Substances; D008565:Membrane Proteins; D010446:Peptide Fragments; D010450:Endopeptidases; D002918:Chymotrypsin; D019286:Endopeptidase K