Autoprotease

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An autoprotease (autopeptidase) is an enzyme that can cleave itself; H. has itself as a substrate . The autoproteases break peptide bonds within their own molecule and are mostly specific for particular amino acid sequences. Therefore they are also assigned to the group of endopeptidases .

The autoproteases often occur in viruses , which is where they were first discovered. Through the autoproteolysis of an enzyme, it is either separated from a larger precursor protein and only then released (e.g. in the Flaviviridae and Pestiviridae ) or activated through an autoproteolytic cleavage in order to be able to cleave another peptide as the actual substrate.

Some autoproteases are known to require additional cellular or viral cofactors in order to initiate activation by autoproteolysis. This is e.g. B. for the NS2 protease of the hepatitis C virus , which requires the NS3 protease as a cofactor for autoproteolytic cleavage and activation. Because the activation of an autoprotease depends on cofactors, they play a special role in the regulation of protein-splitting enzymes in cell metabolism and the replication of viruses.

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  1. ^ CS Hahn, EG Strauss, JH Strauss: Sequence analysis of three Sindbis virus mutants temperature-sensitive in the capsid protein autoprotease. In: PNAS . 82 (14), 1985, pp. 4648-4652. PMID 3895223 .
  2. ↑ G. Muyldermans, MC San Gabriel, R. Hamers, L. Wyns: Expression in E. coli and purification of the active autoprotease P20 of classical swine fever virus. In: Virus Genes. 13 (2), 1996, pp. 135-142. PMID 8972567 .
  3. ↑ P. Neddermann, L. Tomei, C. Steinkuhler et al: The nonstructural proteins of the hepatitis C virus: structure and functions . In: Biological Chemistry . 378 (6), 1997, pp. 469-476. PMID 9224925 .
  4. ↑ T. Moldoveanu, CM Hosfield, D. Lim, Z. Jia, Davies PL: calpain silencing by a reversible intrinsic mechanism. In: Nat Struct Biol . 10 (5), 2003, pp. 371-378. PMID 12665854 .
  5. ↑ T. Lackner, HJ Thiel, N. Tautz: Dissection of a viral autoprotease elucidates a function of a cellular chaperone in proteolysis . In: PNAS. 103 (5), 31, 2006, pp. 1510-1515. PMID 16432213 .

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