1. M protein of type 12 Strepto coccus pyogenes. Isolation by electrofocusing and some molecular weight-dependent properties.
- Author
-
Havlícek J
- Subjects
- Antigens, Bacterial analysis, Cell Wall analysis, Hydrolysis, Immunodiffusion, Isoelectric Focusing, Molecular Weight, Sonication, Streptococcus pyogenes immunology, Streptococcus pyogenes pathogenicity, Virulence, Bacterial Proteins immunology, Bacterial Proteins isolation & purification, Streptococcus pyogenes analysis
- Abstract
A method for the isolation and purification of M protein was developed. Purified cell walls were sonically disrupted, solubilized M protein was precipitated by ammonium sulphate and then electrofocused. Both in this material and in hot acid extracts type-specific trypsin-sensitive antigens with two separately precipitating moieties were found. Evidence is adduced showing that they both belong to the M protein complex. The molecular weight of our purified M protein ranged between 400,000 and 20,000 daltons, giving a peak at 150,000 daltons. The pI of this material was found to be 5.4-5.6. There were marked differences between the behaviour of the low, medium and high molecular weight fractions obtained from purified M protein by gel filtration.
- Published
- 1975