title: A comparison of different methods of extraction of the M-protein from Streptococcus equi.
abstract: The molecular weights of the proteins produced in different extracts of Streptococcus equi were compared on immunoblots with antisera against acid extracted and mutanolysin extracted M-protein. Acid and alkaline extracts of S. equi contained some peptides of similar molecular weight that reacted with antiserum against an acid extracted 41,000 m.w. fragment suggesting that these fragments contained common epitopes. Comparison of the amino acid compositions of the 35,000 m.w. fragment of the alkaline extract and the 41,000 m.w. fragment of the acid extract suggest that these immunologically reactive fragments were probably derived from the same protein. Little cross-reactivity was observed between antisera against S. equi acid extracted protein and the native 58,000 m.w. M-protein. This suggests that conformational epitopes on the native M molecule are not present after acid treatment.
authors.affiliation: Department of Veterinary Microbiology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
authors.forename: J S
authors.initials: JS
authors.lastname: Boschwitz
authors.forename: M H
authors.initials: MH
authors.lastname: Groschup
authors.forename: J F
authors.initials: JF
authors.lastname: Timoney
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000942:Antigens, Bacterial / Q000032:analysis / Q000302:isolation & purification*; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins / Q000032:analysis / Q000302:isolation & purification*; D002352:Carrier Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D010450:Endopeptidases; D000939:Epitopes / Q000032:analysis; D015151:Immunoblotting; D008970:Molecular Weight; D010446:Peptide Fragments / Q000032:analysis; D013291:Streptococcus / Q000032:analysis*
chemical_list: D000596:Amino Acids; D000942:Antigens, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D000939:Epitopes; D010446:Peptide Fragments; C014689:streptococcal M protein; D010450:Endopeptidases; C021816:mutanolysin