Biomaterial Database

Cleavage of the third component of complement (C3) by mannose-binding protein-associated serine protease (MASP) with subsequent complement activation. 1995

M Matsushita, and T Fujita

Department of Biochemistry, Fukushima Medical College, Japan.

We have previously shown that a novel C1s-like serine protease termed MBP-associated serine protease (MASP) is responsible for activation of the complement cascade initiated by mannose-binding protein (MBP). In this communication, we report that MASP is unique in having the proteolytic capacity to cleave C3 with subsequent activation of the alternative pathway, a capacity which C1s lacks.

UI	MeSH Term	Description	Entries
D008358	Mannose	A hexose or fermentable monosaccharide and isomer of glucose from manna, the ash Fraxinus ornus and related plants. (From Grant & Hackh's Chemical Dictionary, 5th ed & Random House Unabridged Dictionary, 2d ed)	D-Mannose,Mannopyranose,Mannopyranoside,D Mannose
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D003167	Complement Activation	The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.	Activation, Complement,Activations, Complement,Complement Activations
D003173	Complement C1s	A 77-kDa subcomponent of complement C1, encoded by gene C1S, is a SERINE PROTEASE existing as a proenzyme (homodimer) in the intact complement C1 complex. Upon the binding of COMPLEMENT C1Q to antibodies, the activated COMPLEMENT C1R cleaves C1s into two chains, A (heavy) and B (light, the serine protease), linked by disulfide bonds yielding the active C1s. The activated C1s, in turn, cleaves COMPLEMENT C2 and COMPLEMENT C4 to form C4b2a (CLASSICAL C3 CONVERTASE).	C 1 Esterase,C1 Esterase,C1s Complement,Complement 1 Esterase,Complement 1s,Complement Component 1s,C1s, Complement,Complement, C1s,Component 1s, Complement,Esterase, C 1,Esterase, C1,Esterase, Complement 1
D003176	Complement C3	A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.	C3 Complement,C3 Precursor,Complement 3,Complement C3 Precursor,Complement Component 3,Precursor-Complement 3,Pro-C3,Pro-Complement 3,C3 Precursor, Complement,C3, Complement,Complement, C3,Component 3, Complement,Precursor Complement 3,Precursor, C3,Precursor, Complement C3,Pro C3,Pro Complement 3
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D006868	Hydrolysis	The process of cleaving a chemical compound by the addition of a molecule of water.
D012697	Serine Endopeptidases	Any member of the group of ENDOPEPTIDASES containing at the active site a serine residue involved in catalysis.	Serine Endopeptidase,Endopeptidase, Serine,Endopeptidases, Serine
D050606	Mannose-Binding Protein-Associated Serine Proteases	Serum serine proteases which participate in COMPLEMENT ACTIVATION. They are activated when complexed with the MANNOSE-BINDING LECTIN, therefore also known as Mannose-binding protein-Associated Serine Proteases (MASPs). They cleave COMPLEMENT C4 and COMPLEMENT C2 to form C4b2a, the CLASSICAL PATHWAY C3 CONVERTASE.	MASP,MASP Proteases,MASP-Related Protein,MASPs,MBL-Associated Serine Proteases,MBP-Associated Serine Protease,MBP-Associated Serine Protease-Related Protein,Mannan-Binding Lectin Serine Proteases,Mannose-Binding Protein-Associated Serine Protease,MASP Related Protein,MBL Associated Serine Proteases,MBP Associated Serine Protease,MBP Associated Serine Protease Related Protein,Mannan Binding Lectin Serine Proteases,Mannose Binding Protein Associated Serine Protease,Proteases, MASP,Protein, MASP-Related,Serine Protease, MBP-Associated,Serine Proteases, MBL-Associated
D037102	Lectins	Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.	Animal Lectin,Animal Lectins,Isolectins,Lectin,Isolectin,Lectin, Animal,Lectins, Animal