Limited proteolysis of the surface of type 1 Streptococcus pyogenes by pepsin gives rise to fragment Pep M1 of Mr 20270 as the main product which covers the N-terminal part of the M protein. The amino acid sequence was determined of the N-terminal region of the M protein representing the most exposed part of the molecule on the surface fibrils of streptococcal cells, which seems to be very important for the differentiation of the individual serological types. The sequence differs from the homologous N-terminal sequences of types 5, 6 and 24, and shows a homology with sequences repeating in the chain of type 24. Fragment Pep M1 binds to fibrinogen; the absence of its 30 N-terminal amino acid residues, however, abolishes this interaction which is believed to play a role in the virulence of S. pyogenes.
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http://dx.doi.org/10.1016/0014-5793(86)81064-x | DOI Listing |
Infect Disord Drug Targets
January 2025
HCA Healthcare Las Palmas/Del Sol Internal Medicine Program.
Background: Streptococcal Toxic Shock Syndrome (STSS) is a life-threatening condition caused by bacterial toxins. The STSS triad encompasses high fever, hypotensive shock, and a "sunburn-like" rash with desquamation. STSS, like Toxic Shock Syndrome (TSS), is a rare complication of streptococcal infec-tions caused by Group A Streptococcus (GAS), Streptococcal pyogenes (S.
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January 2025
Department of Infectious Diseases, The University of Melbourne at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
Critical to the success of CRISPR-based diagnostic assays is the selection of a diagnostic target highly specific to the organism of interest, a process often requiring iterative cycles of manual selection, optimisation, and redesign. Here we present PathoGD, a bioinformatic pipeline for rapid and high-throughput design of RPA primers and gRNAs for CRISPR-Cas12a-based pathogen detection. PathoGD is fully automated, leverages publicly available sequences and is scalable to large datasets, allowing rapid continuous monitoring and validation of primer/gRNA sets to ensure ongoing assay relevance.
View Article and Find Full Text PDFmSphere
January 2025
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
Unlabelled: During infection, bacterial pathogens rely on secreted virulence factors to manipulate the host cell. However, in gram-positive bacteria, the molecular mechanisms underlying the folding and activity of these virulence factors after membrane translocation are not clear. Here, we solved the protein structures of two secreted parvulin and two secreted cyclophilin-like peptidyl-prolyl isomerase (PPIase) ATP-independent chaperones found in gram-positive streptococcal species.
View Article and Find Full Text PDFInfect Immun
January 2025
Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
Streptococcal pyogenic exotoxins (Spe proteins) secreted by (group A , GAS) are responsible for scarlet fever and streptococcal toxic shock syndrome. Most Spes are superantigens that cause excessive inflammation by activating large numbers of T cells. However, Streptococcal pyogenic exotoxin B (SpeB) is an exception, which is pro-inflammatory through its protease activity.
View Article and Find Full Text PDFiScience
January 2025
Institute of Research and Development, Duy Tan University, Da Nang, Vietnam.
is a Gram-positive bacterium, also known as Group A (GAS), that has become a significant threat to the healthcare system, infecting more than 18 million people and resulting in more than 500,000 deaths annually worldwide. GAS infection rates decreased gradually during the 20th century in Western countries, largely due to improved living conditions and access to antibiotics. However, post-COVID-19, the situation has led to a steep increase in GAS infection rates in Europe, the United States, Australia, and New Zealand, which triggers a global concern.
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