IgA protease (EC 3.4.21.72, IgA-specific serine endopeptidase, IgA proteinase, IgA-specific proteinase, immunoglobulin A protease, immunoglobulin A proteinase) is an enzyme.[1][2] This enzyme catalyses the following chemical reaction[reaction equation needed]
| IgA-specific serine endopeptidase | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| EC no. | 3.4.21.72 | ||||||||
| CAS no. | 55127-02-1 | ||||||||
| Databases | |||||||||
| IntEnz | IntEnz view | ||||||||
| BRENDA | BRENDA entry | ||||||||
| ExPASy | NiceZyme view | ||||||||
| KEGG | KEGG entry | ||||||||
| MetaCyc | metabolic pathway | ||||||||
| PRIAM | profile | ||||||||
| PDB structures | RCSB PDB PDBe PDBsum | ||||||||
| |||||||||
It performs cleavage of human immunoglobulin A subclass 1 (IgA1) molecules in the heavy chain hinge region but does not cleave IgA2. No small molecule substrates are known.
This enzyme is secreted by Gram-negative bacteria Neisseria gonorrhoeae, Neisseria meningitidis, Haemophilus influenzae, and Gram-positive Streptococcus pneumoniae.
The action of IgA protease allows the above mentioned bacteria to adhere to mucous membranes.
An IgA protease is a highly specific 106kDa enzyme that cleaves amino acid sequences of certain proteins. The natural substrate of IgA proteases is immunoglobulin A, hence its name. The enzyme is in fact capable of cleavage of proteins with the amino acid sequence Cleaves N-X-Z-Pro-Pro/-Y-Pro-C, where the X in the sequence preferably is a Proline or Serine; the Y = Threonine, Serine or Alanine; and Z preferably is Arginine or Threonine. Because of the sequence that the enzyme is able to cleave, it is also called IgAse Pro-Pro-Y-Pro. Thus, the IgA protease act by cleaving the proline-rich hinge region of the heavy chain of IgA1. Three major bacteria, Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae type B, release the IgA protease which destroys IgA.[3]
See also
editReferences
edit- ^ Plaut AG (1983). "The IgA1 proteases of pathogenic bacteria". Annual Review of Microbiology. 37 (1): 603–22. doi:10.1146/annurev.mi.37.100183.003131. PMID 6416146.
- ^ Bachovchin WW, Plaut AG, Flentke GR, Lynch M, Kettner CA (March 1990). "Inhibition of IgA1 proteinases from Neisseria gonorrhoeae and Hemophilus influenzae by peptide prolyl boronic acids". The Journal of Biological Chemistry. 265 (7): 3738–43. doi:10.1016/S0021-9258(19)39656-5. PMID 2105953.
- ^ Qiu J, Brackee GP, Plaut AG (March 1996). "Analysis of the specificity of bacterial immunoglobulin A (IgA) proteases by a comparative study of ape serum IgAs as substrates". Infection and Immunity. 64 (3): 933–7. doi:10.1128/iai.64.3.933-937.1996. PMC 173859. PMID 8641803.
External links
edit- IgA-specific+serine+endopeptidase at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
