title: Dissociation of intermolecular disulfide bonds in P22 tailspike protein intermediates in the presence of SDS.
abstract: Each chain of the native trimeric P22 tailspike protein has eight cysteines that are reduced and buried in its hydrophobic core. However, disulfide bonds have been observed in the folding pathway and they are believed to play a critical role in the registration of the three chains. Interestingly, in the presence of sodium dodecyl sulfate (SDS) only monomeric chains, rather than disulfide-linked oligomers, have been observed from a mixture of folding intermediates. Here we show that when the oligomeric folding intermediates were separated from the monomer by native gel electrophoresis, the reduction of intermolecular disulfide bonds did not occur in the subsequent second-dimension SDS-gel electrophoresis. This result suggests that when tailspike monomer is present in free solution with SDS, the partially unfolded tailspike monomer can facilitate the reduction of disulfide bonds in the tailspike oligomers.
authors.affiliation: Department of Chemical Engineering, University of Delaware, Newark 19716, USA.
authors.forename: Junghwa
authors.initials: J
authors.lastname: Kim
authors.forename: Anne Skaja
authors.initials: AS
authors.lastname: Robinson
mesh_terms: D019281:Dimerization; D004220:Disulfides / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D006026:Glycoside Hydrolases; D017510:Protein Folding; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology*; D017376:Viral Tail Proteins / Q000737:chemistry*
chemical_list: D004220:Disulfides; D017376:Viral Tail Proteins; D012967:Sodium Dodecyl Sulfate; D006026:Glycoside Hydrolases; C083268:tailspike protein, bacteriophage