Collect. Czech. Chem. Commun. 1990, 55, 2562-2567

Amino terminal sequence of type 3 streptococcal M protein extraction products

Ivan Kluha, Otto Kühnemundb, Manfred Pavlíka, Ladislav Moráveka and Jiří Havlíčekc

a Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6, Czechoslovakia
b Central Institute of Microbiology and Experimental Therapy, Academy of Sciences of G.D.R., Jena, G.D.R.
c Institute of Hygiene and Epidemiology, 100 00 Prague, Czechoslovakia


The amino terminal hypervariable part of the M protein molecule was chosen as a basis for the preparation of a synthetic peptide vaccine against group A streptococci. As part of the mapping of various serological types the main products of extraction of type M Streptococcus pyogeneswith limited pepsin (Pep) hydrolysis at pH 5.5 and with phage-associated lysin (PAL) were sequenced. Two entirely different sequences were obtained. The sequence of PAL M3 shows the absence of the α-helical potential in the shorter N-terminal region as is characteristic of the N-terminus of the M protein molecule. The main product of limited hydrolysis Pep M3 (pH 5.5), which shows the presence of the α-helical potential from the very amino terminal residue of its chain, does not involve most likely the proper N-terminus of the M protein. Extraction with pepsin under conditions of very limited proteolysis (pH 5.8) yielded a fragment with N-terminal sequence identical with that of PAL M3 (extracted nonproteolytically).