scholarly journals Streptococcal M protein extracted by nonionic detergent. III. Correlation between immunological cross-reactions and structural similarities with implications for antiphagocytosis.

1978 ◽  
Vol 147 (6) ◽  
pp. 1771-1778 ◽  
Author(s):  
V A Fischetti
Keyword(s):  
Sequence Variation ◽  
Peptide Mapping ◽  
Structural Similarity ◽  
M Protein ◽  
Cross Reactions ◽  
Streptococcal M Protein ◽  
Mapping System ◽  
M Proteins ◽  
Protein Molecules ◽  
Nonionic Detergent

Three immunologically cross-reactive and non-cross-reactive streptococcal M proteins were analyzed by a chromatographic tryptic peptide mapping system. The results indicate that cross-reactions correlate with the extent of structural similarity among the M protein molecules analyzed. The data also reveal that free lysine is released by the action of trypsin from these three M proteins, suggesting a common lys-lys or arg-lys sequence. In addition, only one peptide has been found to be common within all three M types. This limited structural relatedness among the three M proteins examined indicates that sequence variation plays a major role in the immunological specificity of the M antigens. However, despite sequence variation, all M protein molecules have a common antiphagocytic activity. The fact that no common opsonic antibody has yet been found, even against limited M types, argues against this biological activity being solely the result of a common sequence. Based on these data, it is suggested that the antiphagocytic effect of M protein may be due to a conformationally created environment on the surface of the molecule which is selected by both immunological and biological pressure.

scholarly journals Evidence for two distinct classes of streptococcal M protein and their relationship to rheumatic fever.

1989 ◽  
Vol 169 (1) ◽  
pp. 269-283 ◽  
Author(s):  
D Bessen ◽  
K F Jones ◽  
V A Fischetti
Keyword(s):  
Rheumatic Fever ◽  
Class Ii ◽  
Class I ◽  
M Protein ◽  
Repeat Region ◽  
Streptococcal M Protein ◽  
Antigenic Relatedness ◽  
M Proteins ◽  
Protein Molecules ◽  
Definition Of

The antigenic relatedness of surface-exposed portions of M protein molecules derived from group A streptococcal isolates representing more than 50 distinct serotypes was examined. The data indicate that the majority of serotypes fall into two major classes. Class I M protein molecules share a surface-exposed, antigenic domain comprising the C repeat region defined for M6 protein. The C repeat region of M6 protein is located adjacent to the COOH-terminal side of the pepsin-susceptible site. In contrast, Class I M proteins display considerably less antigenic relatedness to the B repeat region of M6 protein, which lies immediately NH2-terminal to the pepsin site. Surface-exposed portions of Class II M proteins lack antigenic epitopes that define the Class I molecules. Studies in the 1970s demonstrated that M protein serotypes can be divided into two groups based on both immunoreactivity directed to an unknown surface antigen (termed M-associated protein) and production of serum opacity factor. These two groups closely parallel our current definition of Class I and Class II serotypes. Both classes retain the antiphagocytic property characteristic of M protein, and Class II M proteins share some immunodeterminants with Class I M proteins, although the shared determinants do not appear to be exposed on the streptococcal surface. Nearly all streptococcal serotypes associated with outbreaks of acute rheumatic fever express M protein of a Class I serotype. Thus, the surface-exposed, conserved C repeat domain of Class I serotypes may be a virulence determinant for rheumatic fever.

scholarly journals Sequence of myosin-crossreactive epitopes of streptococcal M protein.

1986 ◽  
Vol 164 (5) ◽  
pp. 1785-1790 ◽  
Author(s):  
J B Dale ◽  
E H Beachey
Keyword(s):  
Synthetic Peptide ◽  
Synthetic Peptides ◽  
Human Myocardium ◽  
M Protein ◽  
Cardiac Myosin ◽  
Streptococcal M Protein ◽  
M Proteins ◽  
Group A ◽  
Inhibition Studies ◽  
Rheumatic Heart

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.

scholarly journals Streptococcal M protein extracted by nonionic detergent. I. Properties of the antiphagocytic and type-specific molecules.

1976 ◽  
Vol 144 (1) ◽  
pp. 32-53 ◽  
Author(s):  
V A Fischetti ◽  
E C Gotschlich ◽  
G Siviglia ◽  
J B Zabriskie
Keyword(s):  
Cell Wall ◽  
M Protein ◽  
Multiple Form ◽  
Streptococcal Cell Wall ◽  
Streptococcal M Protein ◽  
Physical Chemical ◽  
Immunological Tests ◽  
Multiple Protein ◽  
Nonionic Detergent ◽  
Group A

Group A streptococcal M protein was extracted with nonionic detergent and subjected to a number of physical, chemical, and immunological tests. M protein thus extracted was composed of multiple protein bands, ranging from 35,000 down to 6,000 daltons, all having type-specific precipitating activity. The anti-phagocytic proteins, however, were limited to three molecular species having mol wt of 28,000, 31,000, and 35,000 daltons, and could be separated from those proteins that had only type specificity. Physical studies indicated that these proteins existed as individual asymmetrical molecules which were not aggregated. By radiolabeling M protein on living streptococci, it was determined that these protein bands were found on the streptococcal cell wall in this multiple form. Also, by pulse chase experiments supported by chemical and immunological data, evidence was obtained strongly suggesting that the smaller, type-specific molecules are used to assemble the larger, antiphagocytic proteins.

scholarly journals Protective and heart-crossreactive epitopes located within the NH2 terminus of type 19 streptococcal M protein.

1988 ◽  
Vol 167 (6) ◽  
pp. 1849-1859 ◽  
Author(s):  
M S Bronze ◽  
E H Beachey ◽  
J B Dale
Keyword(s):  
Amino Acids ◽  
Heart Disease ◽  
Primary Structure ◽  
Synthetic Peptide ◽  
Human Myocardium ◽  
M Protein ◽  
Streptococcal M Protein ◽  
M Proteins ◽  
Rheumatic Heart

M protein was purified to homogeneity from limited pepsin digests of intact type 19 streptococci (pep M19). The purified pep M19 when emulsified in CFA and injected into rabbits evoked type-specific and crossreactive opsonic antibodies, as well as heart-crossreactive antibodies. The NH2-terminal primary structure of pep M19 was determined and a peptide copying the first 24 amino acids [SM19(1-24)C] was chemically synthesized. Rabbits that were immunized with the unconjugated peptide developed antibodies that recognized the native pep M19, as determined by ELISA, and opsonic antibodies against type 19 streptococci, as determined by in vitro opsonophagocytosis tests. The synthetic peptide also evoked antibodies that crossreacted with a 60-kD sarcolemmal membrane protein of human myocardium. By using overlapping synthetic subpeptides as immunoinhibitors, the opsonic and heart-crossreactive epitopes of SM19(1-24)C were localized to SM19(11-24)C. Our data confirm the presence of heart-crossreactive epitopes within the primary structure of pep M19 and show that these potentially harmful autoimmune epitopes may be located in the NH2-terminal regions of certain M proteins. We conclude that continued efforts to identify the primary structures of protective and heart-crossreactive epitopes will be necessary to elucidate the pathogenesis of acute rheumatic heart disease and to develop safe and effective streptococcal vaccines.

scholarly journals Multiple, heart-cross-reactive epitopes of streptococcal M proteins.

1985 ◽  
Vol 161 (1) ◽  
pp. 113-122 ◽  
Author(s):  
J B Dale ◽  
E H Beachey
Keyword(s):  
Membrane Proteins ◽  
Heart Tissue ◽  
Human Myocardium ◽  
M Protein ◽  
Antigenic Determinants ◽  
Serotype Distribution ◽  
Present Evidence ◽  
Sarcolemmal Membrane ◽  
Streptococcal M Protein ◽  
M Proteins

We present evidence that a highly purified pepsin extract of type 5 streptococcal M protein (pep M5) contains at least three epitopes that are cross-reactive with sarcolemmal membrane proteins of human myocardium. The tissue-cross-reactive determinants of pep M5 are also partially shared with pep M6 and pep M19. Three rabbits immunized with a single 300 micrograms dose of pep M5 developed significant levels of heart-cross-reactive antibodies, as determined by indirect immunofluorescence tests. All three sera also contained antibodies that cross-reacted with pep M6 and pep M19. The heart tissue--specific antibodies that were eluted from sarcolemmal membranes opsonized types 5, 6, and 19 streptococci, indicating that they were directed against protective M protein epitopes on the surface of virulent organisms. Immunofluorescence inhibition tests, using purified M proteins as soluble inhibitors of heart-cross-reactive antibodies, revealed the number and M protein serotype distribution of the tissue-cross-reactive epitopes. Immunoblot analyses demonstrated the sarcolemmal membrane proteins containing the various cross-reactive antigenic determinants.

scholarly journals The Plasminogen-Binding Group A Streptococcal M Protein-Related Protein Prp Binds Plasminogen via Arginine and Histidine Residues

2006 ◽  
Vol 189 (4) ◽  
pp. 1435-1440 ◽  
Author(s):  
Martina L. Sanderson-Smith ◽  
Mark Dowton ◽  
Marie Ranson ◽  
Mark J. Walker
Keyword(s):  
Binding Site ◽  
Group A Streptococcus ◽  
Invasive Disease ◽  
Site Directed Mutagenesis ◽  
M Protein ◽  
Histidine Residues ◽  
Streptococcal M Protein ◽  
M Proteins ◽  
Lysine Residues ◽  
Group A

ABSTRACT The migration of the human pathogen Streptococcus pyogenes (group A streptococcus) from localized to deep tissue sites may result in severe invasive disease, and sequestration of the host zymogen plasminogen appears crucial for virulence. Here, we describe a novel plasminogen-binding M protein, the plasminogen-binding group A streptococcal M protein (PAM)-related protein (Prp). Prp is phylogenetically distinct from previously described plasminogen-binding M proteins of group A, C, and G streptococci. While competition experiments indicate that Prp binds plasminogen with a lower affinity than PAM (50% effective concentration = 0.34 μM), Prp nonetheless binds plasminogen with high affinity and at physiologically relevant concentrations of plasminogen (Kd = 7.8 nM). Site-directed mutagenesis of the putative plasminogen binding site indicates that unlike the majority of plasminogen receptors, Prp does not interact with plasminogen exclusively via lysine residues. Mutagenesis to alanine of lysine residues Lys96 and Lys101 reduced but did not abrogate plasminogen binding by Prp. Plasminogen binding was abolished only with the additional mutagenesis of Arg107 and His108 to alanine. Furthermore, mutagenesis of Arg107 and His108 abolished plasminogen binding by Prp despite the presence of Lys96 and Lys101 in the binding site. Thus, binding to plasminogen via arginine and histidine residues appears to be a conserved mechanism among plasminogen-binding M proteins.

scholarly journals Superantigenicity of streptococcal M protein.

1990 ◽  
Vol 172 (1) ◽  
pp. 359-362 ◽  
Author(s):  
M Tomai ◽  
M Kotb ◽  
G Majumdar ◽  
E H Beachey
Keyword(s):  
T Cells ◽  
Mhc Class Ii ◽  
Class Ii ◽  
M Protein ◽  
Streptococcal M Protein ◽  
Human T Cells ◽  
M Proteins ◽  
Group A ◽  
Cell Mitogen ◽  
Antigen Presenting

M proteins that define the serotypes of group A streptococci are powerful blastogens for human T lymphocytes. The mechanism by which they activate T cells was investigated and compared with the conventional T cell mitogen phytohemagglutinin, and the known superantigen staphylococcal enterotoxin B. Although major histocompatibility complex (MHC) class II molecules are required for presentation, there is no MHC restriction, since allogeneic class II molecules presented the bacterial protein to human T cells. Type 5 M protein appears to bind class II molecules on the antigen-presenting cells and stimulate T cells bearing V beta 8 sequences. Our results indicate that this streptococcal M protein is a superantigen and suggest a possible mechanism of its role in the pathogenesis of the postinfectious autoimmune sequelae.

scholarly journals Streptococcal M protein extracted by nonionic detergent. II. Analysis of the antibody response to the multiple antigenic determinants of the M-protein molecule.

1977 ◽  
Vol 146 (4) ◽  
pp. 1108-1123 ◽  
Author(s):  
V A Fischetti
Keyword(s):  
Solid Phase ◽  
Protein Molecule ◽  
The Other ◽  
M Protein ◽  
Antigenic Determinants ◽  
Specific Response ◽  
Human Beings ◽  
Inhibition Assay ◽  
Streptococcal M Protein ◽  
Nonionic Detergent

Purified streptococcal M protein extracted by nonionic detergent was used in an RIA and a solid-phase radiocompetitive inhibition assay to determine the nature of the immune response in both human beings and hyperimmunized rabbits to this complex antiphagocytic antigen. Results indicate that a type-specific response to an M antigen with the development of opsonic antibodies is the result of antibodies directed against the majority of the antigenic determinants of the molecule. Cross-reactions between certain M types on the other hand, are represented by antibodies directed against only a small percentage of these antigenic determinants. Results also suggest that avidity may play a role in the action of opsonic antibodies. However, the data indicate that factors besides avidity (i.e. sites bound by the antibodies) also seem essential for opsonization.

scholarly journals Role of Small Envelope Protein in Sustaining the Intracellular and Extracellular Levels of Hepatitis B Virus Large and Middle Envelope Proteins

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 613
Author(s):  
Jing Zhang ◽  
Yongxiang Wang ◽  
Shuwen Fu ◽  
Quan Yuan ◽  
Qianru Wang ◽  
...  
Keyword(s):  
Envelope Proteins ◽  
Full Length ◽  
M Protein ◽  
Intracellular Level ◽  
S Protein ◽  
L Protein ◽  
M Proteins ◽  
B Virus ◽  
Subviral Particle ◽  
Genotype A

Hepatitis B virus (HBV) expresses co-terminal large (L), middle (M), and small (S) envelope proteins. S protein drives virion and subviral particle secretion, whereas L protein inhibits subviral particle secretion but coordinates virion morphogenesis. We previously found that preventing S protein expression from a subgenomic construct eliminated M protein. The present study further examined impact of S protein on L and M proteins. Mutations were introduced to subgenomic construct of genotype A or 1.1mer replication construct of genotype A or D, and viral proteins were analyzed from transfected Huh7 cells. Mutating S gene ATG to prevent expression of full-length S protein eliminated M protein, reduced intracellular level of L protein despite its blocked secretion, and generated a truncated S protein through translation initiation from a downstream ATG. Truncated S protein was secretion deficient and could inhibit secretion of L, M, S proteins from wild-type constructs. Providing full-length S protein in trans rescued L protein secretion and increased its intracellular level from mutants of lost S gene ATG. Lost core protein expression reduced all the three envelope proteins. In conclusion, full-length S protein could sustain intracellular and extracellular L and M proteins, while truncated S protein could block subviral particle secretion.

scholarly journals Two Overlapping Domains of a Lyssavirus Matrix Protein That Acts on Different Cell Death Pathways

2010 ◽  
Vol 84 (19) ◽  
pp. 9897-9906 ◽  
Author(s):  
Florence Larrous ◽  
Alireza Gholami ◽  
Shahul Mouhamad ◽  
Jérôme Estaquier ◽  
Hervé Bourhy
Keyword(s):  
Cell Death ◽  
Amino Acid ◽  
Matrix Protein ◽  
Full Length ◽  
M Protein ◽  
Genotype 3 ◽  
Cell Death Pathways ◽  
Acid Fragment ◽  
M Proteins ◽  
Cellular Apoptosis

ABSTRACT The lyssavirus matrix (M) protein induces apoptosis. The regions of the M protein that are essential for triggering cell death pathways are not yet clearly defined. We therefore compared the M proteins from two viruses that have contrasting characteristics in terms of cellular apoptosis: a genotype 3 lyssavirus, Mokola virus (MOK), and a genotype 1 rabies virus isolated from a dog from Thailand (THA). We identified a 20-amino-acid fragment (corresponding to positions 67 to 86) that retained the cell death activities of the full-length M protein from MOK via both the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and inhibition of cytochrome c oxidase (CcO) activity. We found that the amino acids at positions 77 and 81 have an essential role in triggering these two cell death pathways. Directed mutagenesis demonstrated that the amino acid at position 77 affects CcO activity, whereas the amino acid at position 81 affects TRAIL-dependent apoptosis. Mutations in the full-length M protein that compromised induction of either of these two pathways resulted in delayed apoptosis compared with the time to apoptosis for the nonmutated control.

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