| Anaphylotoxin-like domain | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
 Structure of porcine C5adesArg.[1] | |||||||||||
| Identifiers | |||||||||||
| Symbol | ANATO | ||||||||||
| Pfam | PF01821 | ||||||||||
| InterPro | IPR000020 | ||||||||||
| SMART | ANATO | ||||||||||
| PROSITE | PDOC00906 | ||||||||||
| SCOP2 | 1c5a / SCOPe / SUPFAM | ||||||||||
| |||||||||||
Anaphylatoxins, or complement peptides, are fragments (C3a, C4a and C5a) that are produced as part of the activation of the complement system.[2] Complement components C3, C4 and C5 are large glycoproteins that have important functions in the immune response and host defense.[3] They have a wide variety of biological activities and are proteolytically activated by cleavage at a specific site, forming a- and b-fragments.[4] A-fragments form distinct structural domains of approximately 76 amino acids, coded for by a single exon within the complement protein gene. The C3a, C4a and C5a components are referred to as anaphylatoxins:[4][5] they cause smooth muscle contraction, vasodilation, histamine release from mast cells, and enhanced vascular permeability.[5] They also mediate chemotaxis, inflammation, and generation of cytotoxic oxygen radicals.[5] The proteins are highly hydrophilic, with a mainly alpha-helical structure held together by 3 disulfide bridges.[5]
- ^ Williamson MP, Madison VS (March 1990). "Three-dimensional structure of porcine C5adesArg from 1H nuclear magnetic resonance data". Biochemistry. 29 (12): 2895–905. doi:10.1021/bi00464a002. PMID 2337573.
- ^ Hugli TE (1986). "Biochemistry and biology of anaphylatoxins". Complement. 3 (3): 111–27. doi:10.1159/000467889. PMID 3542363.
- ^ Fritzinger DC, Petrella EC, Connelly MB, Bredehorst R, Vogel CW (December 1992). "Primary structure of cobra complement component C3". Journal of Immunology. 149 (11): 3554–62. doi:10.4049/jimmunol.149.11.3554. PMID 1431125. S2CID 10452671.
- ^ a b Ogata RT, Rosa PA, Zepf NE (October 1989). "Sequence of the gene for murine complement component C4". The Journal of Biological Chemistry. 264 (28): 16565–72. doi:10.1016/S0021-9258(19)84744-0. PMID 2777798.
- ^ a b c d Gennaro R, Simonic T, Negri A, Mottola C, Secchi C, Ronchi S, Romeo D (February 1986). "C5a fragment of bovine complement. Purification, bioassays, amino-acid sequence and other structural studies". European Journal of Biochemistry. 155 (1): 77–86. doi:10.1111/j.1432-1033.1986.tb09460.x. PMID 3081348.