User:Gag224/Wikipedia.org/wiki/M protein (Streptococcus)
There are over 200 known serotypes of M proteins, which is what allows an individual to become infected with more than one member of the Streptococcus family. [1] Of the known serotypes, M1 and M3 are most commonly associated with pneumonia and deep soft tissue infections.[2]
Structure[edit]
Under a microscope, M protein appears as a fibrous coat on the surface of the cell, looking akin to a tennis ball.[1] The structure of the M protein is a fibrillar protein with a non-ideal α-helical coiled-coil configuration.[3] The design of the molecule bears resemblance to other mammalian proteins, such as the rabbit skeletal muscle tropomyosin.[4] The overall size of M protein varies, both between different serotypes and the same serotype, with variations between 41,000 and 60,000 molecular weight.[5]
Both the N-terminus and C-terminus have two unique features. The first is the presence of imperfect repeats in the sequence. Even among closely related M protein types, the repetitions in the N-terminus are not closely related, though they do become much more closely related in the C-Terminus and D-Region. The second is that with the exception of the first 20 residues of the HVR and the C-Terminus except for the last ~50-residues of the D-region, the M protein has α-helical coiled-coil heptad periodicity.[3]
Function[edit]
M proteins bind to many proteins, which include fibrinogen, albumin, plasminogen, immunoglobulin, Factor H and C4b binding protein. The M1 protein can also activate leukocytes, thus inciting inflammatory responses.[6] The C-Terminus region is what allows M proteins to bind to factor H.[7]Although other regions contribute to the M protein’s ability to resist phagocytosis, Streptococcus that do not have M proteins will struggle to survive in human blood that contains phagocytes.[1]
In Streptococcus zooepidemicus, M proteins facilitate the invasion of the brain thanks to membrane vesicles bound to it, which is absorbed by human brain endothelial microvascular cells through endocytosis, causing a disruption to the blood-brain barrier.[8]
Identification of Streptococcus pyogenes[edit]
Regions of the genes of M proteins can be used for the identification of Streptococcus pyogenes and the resulting Group A Streptococcal infection (GAS). By using oligonucleotide probes derived from sequences of the N-terminus region, different serotypes can be identified from one another.[9]
Vaccines[edit]
Development of vaccines that target M proteins is widely sought after, since the M protein is capable of binding many proteins that regulate innate and acquired immune systems. At least one vaccinia virus containing the genes to produce M proteins has shown viability for animal trials.[10]
References[edit]
- ^ a b c Fischetti, Vincent A. (2016), Ferretti, Joseph J.; Stevens, Dennis L.; Fischetti, Vincent A. (eds.), "M Protein and Other Surface Proteins on Streptococci", Streptococcus pyogenes: Basic Biology to Clinical Manifestations, Oklahoma City (OK): University of Oklahoma Health Sciences Center, PMID 26866233, retrieved 2024-04-19
- ^ González-Abad, María José; Alonso Sanz, Mercedes (2020-06). "[Invasive Streptococcus pyogenes infections (2011-2018): EMM-type and clinical presentation]". Anales De Pediatria. 92 (6): 351–358. doi:10.1016/j.anpedi.2019.10.014. ISSN 2341-2879. PMID 31879253.
{{cite journal}}: Check date values in:|date=(help) - ^ a b Ghosh, Partho (2011), Linke, Dirk; Goldman, Adrian (eds.), "The Nonideal Coiled Coil of M Protein and Its Multifarious Functions in Pathogenesis", Bacterial Adhesion: Chemistry, Biology and Physics, Dordrecht: Springer Netherlands, pp. 197–211, doi:10.1007/978-94-007-0940-9_12, ISBN 978-94-007-0940-9, PMC 5541941, PMID 21557065, retrieved 2024-04-19
{{citation}}: CS1 maint: PMC format (link) - ^ Fischetti VA. Streptococcal M protein: molecular design and biological behavior. Clin Microbiol Rev. 1989 Jul;2(3):285-314. doi: 10.1128/CMR.2.3.285. PMID: 2670192; PMCID: PMC358122.
- ^ Fischetti, V. A.; Jones, K. F.; Scott, J. R. (1985-06-01). "Size variation of the M protein in group A streptococci". The Journal of Experimental Medicine. 161 (6): 1384–1401. doi:10.1084/jem.161.6.1384. ISSN 0022-1007. PMC 2187625. PMID 2409199.
- ^ Good, Michael F; Pandey, Manisha; Batzloff, Michael R; Tyrrell, Gregory J (2015-11-02). "Strategic development of the conserved region of the M protein and other candidates as vaccines to prevent infection with group A streptococci". Expert Review of Vaccines. 14 (11): 1459–1470. doi:10.1586/14760584.2015.1081817. ISSN 1476-0584.
- ^ Perez-Casal, J.; Okada, N.; Caparon, M. G.; Scott, J. R. (1995-03). "Role of the conserved C-repeat region of the M protein of Streptococcus pyogenes". Molecular Microbiology. 15 (5): 907–916. doi:10.1111/j.1365-2958.1995.tb02360.x. ISSN 0950-382X. PMID 7596292.
{{cite journal}}: Check date values in:|date=(help) - ^ Pan, Fei; Zhu, Mingli; Liang, Ying; Yuan, Chen; Zhang, Yu; Wang, Yuchang; Fan, Hongjie; Waldor, Matthew K.; Ma, Zhe (2023-06-13). "Membrane vesicle delivery of a streptococcal M protein disrupts the blood-brain barrier by inducing autophagic endothelial cell death". Proceedings of the National Academy of Sciences of the United States of America. 120 (24): e2219435120. doi:10.1073/pnas.2219435120. ISSN 1091-6490. PMID 37276410.
- ^ Kaufhold, A.; Podbielski, A.; Johnson, D. R.; Kaplan, E. L.; Lütticken, R. (1992-09). "M protein gene typing of Streptococcus pyogenes by nonradioactively labeled oligonucleotide probes". Journal of Clinical Microbiology. 30 (9): 2391–2397. doi:10.1128/jcm.30.9.2391-2397.1992. ISSN 0095-1137. PMID 1401004.
{{cite journal}}: Check date values in:|date=(help) - ^ Hruby, D. E.; Hodges, W. M.; Wilson, E. M.; Franke, C. A.; Fischetti, V. A. (1988-08). "Expression of streptococcal M protein in mammalian cells". Proceedings of the National Academy of Sciences of the United States of America. 85 (15): 5714–5717. doi:10.1073/pnas.85.15.5714. ISSN 0027-8424. PMID 3041416.
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