RT Journal Article SR Electronic(1) A1 Vosti, K. L.YR 1978 T1 The Characteristics of M Proteins Purified by Column Chromatography With Hydroxyapatite from Acid Extracts of Streptococcus Pyogenes of Types 1, 3, 6, 12 and 17 JF Journal of Medical Microbiology, VO 11 IS 4 SP 453 OP 462 DO https://doi.org/10.1099/00222615-11-4-453 PB Microbiology Society, SN 1473-5644, AB SUMMARY Purified M proteins were recovered from acid extracts of Streptococcus pyogenes, M-types 1, 3, 6, 12 and 17, by elution from columns of hydroxyapatite of the proteins precipitated with ammonium sulphate. M protein free from non-type-specific antigens was recovered only from M-type 12. Although similar fractions were not recovered from M-types 1, 3, 6 and 17, purified preparations containing a single cross-reactive antigen were obtained. In addition to the M proteins associated with cross-reactive antigens, type-specific antigens that did not stimulate opsonic antibodies were isolated from the acid extracts of M-types 3 and 17. Further study of the purified M proteins revealed molecular weights that ranged from 32 000 to 63 000 daltons, total amino acid compositions that were similar, and N-terminal amino acids that were variable., UL https://www.microbiologyresearch.org/content/journal/jmm/10.1099/00222615-11-4-453