Group A streptococcal M proteins contain epitopes that crossreact with sarcolemmal membrane proteins of human myocardium and myosin. In the present study, synthetic peptide copies spanning the entire 197-residue pepsin extracted fragment of type 5 M protein were used to localize the myosin-crossreactive epitopes of the molecule. Peptide 84-116 inhibited by 75% the binding of myosin-crossreactive antibodies evoked by pep M5, as determined by ELISA. Immunoblot inhibition studies confirmed that peptide 84-116 almost totally inhibited the binding of pep M5 antibodies to the heavy chain of human cardiac myosin. None of the remaining synthetic peptides, including peptide 1-35, which contains protective epitopes, inhibited antibodies binding to myosin. Two of three rabbits immunized with peptide 84-116 developed low but significant levels of antibodies crossreactive with myosin. Identification of the primary structures containing tissue-crossreactive as opposed to protective epitopes should not only allow the development of safe and effective M protein vaccines, but may also provide insights into the pathogenesis of rheumatic heart disease.
Article|
November 01 1986
Sequence of myosin-crossreactive epitopes of streptococcal M protein.
J B Dale
E H Beachey
Online ISSN: 1540-9538
Print ISSN: 0022-1007
J Exp Med (1986) 164 (5): 1785–1790.
Citation
J B Dale, E H Beachey; Sequence of myosin-crossreactive epitopes of streptococcal M protein.. J Exp Med 1 November 1986; 164 (5): 1785–1790. doi: https://doi.org/10.1084/jem.164.5.1785
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