Biomaterial Database

Mapping the fibrinogen-binding domain of serum opacity factor of group a streptococci. 2002

Harry S Courtney, and James B Dale, and David L Hasty

Department of Medicine, University of Tennessee, Memphis, TN, USA. hcourtney@utmem.edu

Serum opacity factor (SOF) is a large, extracellular, and cell-bound protein of group A streptococci that has two known functions, opacification of serum and binding of fibronectin. Herein, we describe a new function of SOF, the binding of fibrinogen. Utilizing purified, truncated recombinant SOF proteins, the fibrinogen-binding domain was localized to a region in the C-terminus of SOF encompassing amino acid residues 844-1047. Western-blot analysis revealed that SOF bound primarily to the beta subunit of fibrinogen. A SOF-negative mutant bound 50% less fibrinogen than did its wild-type parent. Furthermore, fibrinogen blocked the binding of SOF to fibronectin. These data suggest that fibrinogen and fibronectin bind to the same domain within SOF. It remains to be determined whether the binding of fibrinogen to SOF contributes to the virulence of group A streptococci.

UI	MeSH Term	Description	Entries
D010447	Peptide Hydrolases	Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.	Peptidase,Peptidases,Peptide Hydrolase,Protease,Proteases,Proteinase,Proteinases,Proteolytic Enzyme,Proteolytic Enzymes,Esteroproteases,Enzyme, Proteolytic,Hydrolase, Peptide
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011994	Recombinant Proteins	Proteins prepared by recombinant DNA technology.	Biosynthetic Protein,Biosynthetic Proteins,DNA Recombinant Proteins,Recombinant Protein,Proteins, Biosynthetic,Proteins, Recombinant DNA,DNA Proteins, Recombinant,Protein, Biosynthetic,Protein, Recombinant,Proteins, DNA Recombinant,Proteins, Recombinant,Recombinant DNA Proteins,Recombinant Proteins, DNA
D005340	Fibrinogen	Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides A and B, the proteolytic action of other enzymes yields different fibrinogen degradation products.	Coagulation Factor I,Factor I,Blood Coagulation Factor I,gamma-Fibrinogen,Factor I, Coagulation,gamma Fibrinogen
D005353	Fibronectins	Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins.	Cold-Insoluble Globulins,LETS Proteins,Fibronectin,Opsonic Glycoprotein,Opsonic alpha(2)SB Glycoprotein,alpha 2-Surface Binding Glycoprotein,Cold Insoluble Globulins,Globulins, Cold-Insoluble,Glycoprotein, Opsonic,Proteins, LETS,alpha 2 Surface Binding Glycoprotein
D001665	Binding Sites	The parts of a macromolecule that directly participate in its specific combination with another molecule.	Combining Site,Binding Site,Combining Sites,Site, Binding,Site, Combining,Sites, Binding,Sites, Combining
D001667	Binding, Competitive	The interaction of two or more substrates or ligands with the same binding site. The displacement of one by the other is used in quantitative and selective affinity measurements.	Competitive Binding
D013297	Streptococcus pyogenes	A species of gram-positive, coccoid bacteria isolated from skin lesions, blood, inflammatory exudates, and the upper respiratory tract of humans. It is a group A hemolytic Streptococcus that can cause SCARLET FEVER and RHEUMATIC FEVER.	Flesh-Eating Bacteria,Streptococcus Group A,Bacteria, Flesh-Eating
D014161	Transduction, Genetic	The transfer of bacterial DNA by phages from an infected bacterium to another bacterium. This also refers to the transfer of genes into eukaryotic cells by viruses. This naturally occurring process is routinely employed as a GENE TRANSFER TECHNIQUE.	Genetic Transduction,Genetic Transductions,Transductions, Genetic
D015153	Blotting, Western	Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.	Immunoblotting, Western,Western Blotting,Western Immunoblotting,Blot, Western,Immunoblot, Western,Western Blot,Western Immunoblot,Blots, Western,Blottings, Western,Immunoblots, Western,Immunoblottings, Western,Western Blots,Western Blottings,Western Immunoblots,Western Immunoblottings