Antigenic determinants of Streptococcus pyogenes ribosomes.

An attempt has been made to identify the ribosomal proteins responsible for the production of antibodies upon immunization of monkeys with 70S ribosomes of Streptococcus pyogenes group A 29 M type. Identification was carried out by immunoblotting after isolation and separation of the proteins of 70S, 50S and 30S ribosomal particles on one- and two-dimensional gel electrophoresis. Three major proteins of S. pyogenes 70S ribosomes with clearly expressed antigenic properties were identified by Western blotting. One of these proteins belonged to the 50S subunit and the other two--to the 30S ribosomal subunit. We assume that these proteins represent those of group A streptococci. As a result the antibodies are produced first of all against these antigenic proteins in contrast to the others evolutionary conservative ribosomal proteins.