title: Interaction between bile acids and staphylococcal polysaccharide: inhibition of capsule formation in encapsulated mutant strains (taurine+, taurine-) of Staphylococcus aureus.
abstract: In a previous paper, we showed that bile acid derivatives inhibit capsule formation as well as taurine biosynthesis in a taurine+ (Tau+) encapsulated strain of Staphylococcus aureus. In the present study, binding of [14C]cholic acid [( 14C]CA) and [14C]taurocholic acid [( 14C]TA) to the staphylococcal polysaccharide antigen (SPA) of the capsular fraction was examined. The bile acids were found to bind with SPA via taurine of the Tau+ cells. [14C]CA bound with the SPA fraction of the Tau+ strain within 10-30 min, whereas 60-120 min was required in the binding of [14C]TA. Various bile acids competed with cholic acid binding to Tau+ cells which was shown by the inhibition of binding with cholic acid or taurocholic acid but not with glycholic acid. Binding of bile acid derivatives to a Tau- encapsulated mutant or to capsular material from this mutant was not observed.
mesh_terms: D000327:Adsorption; D001647:Bile Acids and Salts / Q000378:metabolism / Q000494:pharmacology*; D002793:Cholic Acids / Q000378:metabolism; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000378:metabolism*; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000378:metabolism; D013654:Taurine / Q000378:metabolism*
chemical_list: D001647:Bile Acids and Salts; D002793:Cholic Acids; D011135:Polysaccharides, Bacterial; D013654:Taurine