Isect silk contains both a Kunitz-type and a unique Kazal-type proteinase inhibitor

0135596 - ENTU-I 20010013 RIV US eng J - Journal Article
Nirmala, Xavier - Kodrík, Dalibor - Žurovec, Michal - Sehnal, František
Isect silk contains both a Kunitz-type and a unique Kazal-type proteinase inhibitor.
European Journal of Biochemistry. Roč. 268, - (2001), s. 2064-2073. ISSN 0014-2956
R&D Projects: GA ČR GA204/00/0019; GA MŠMT ME 204
Institutional research plan: CEZ:AV0Z5007907
Subject RIV: CE - Biochemistry
Impact factor: 2.849, year: 2001

We demonstrated that two of the small peptides present in the silk of the waxmoth, Galleria mellonella , inhibit proteolytic enzymes, and are thus called silk proteinase inhibitors 1 and 2 (SPI 1, SPI 2). The full length cDNA of pre-SPI 1 contains 443 nt and encodes a peptide of 76 amino acid residues, of which 20 make up a signal sequence. The mature SPI 1 (6056.7 Da, 56 residues) is a typical thermostable Kunitz-type proteinase inhibitor. The cDNA of pre-SPI 2 consists of 260 nt and yields a putative secretory peptide of 58 amino acid residues. The functional SPI 2 (3993 Da, 36 residues), is a single-domain Kazal-type proteinase inhibitor with unique structural features. Since SPI 1 and SPI 2 effectively inhibit bacterial and fungal proteinases they may protect silk against microbial degradation.
Permanent Link: http://hdl.handle.net/11104/0033391