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A Fluorogenic Peptide Cleavage Assay to Screen for Proteolytic Activity: Applications for coronavirus spike protein activation
Published on: January 9, 2019
The novel avian protein, AWAK, contains multiple domains with homology to protease inhibitory modules
Christopher J Nile1, Claire L Townes, Barry H Hirst
1Institute for Cell and Molecular Biosciences, Kings Walk, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK.
Abstract:
We report the purification of a 3.5kDa peptide with antimicrobial activity from the mucosa and epithelial cells of chicken intestine. The peptide contains a pattern of cysteines characteristic of a whey acidic protein (WAP) domain and was identified as the carboxy terminal fragment of a novel 767 amino acid avian protein which has a proposed molecular weight of 81kDa. Using the conserved domain database (CDD) we identified this 81kDa protein to contain multiple amino acid motifs with homology to WAP domains and an amino acid motif with homology to a Kunitz proteinase inhibitor domain. We propose to call this avian protein AWAK (Avian WAP motif containing, Kunitz domain containing). The presence of WAP and Kunitz modules suggests that AWAK has proteinase inhibitor activity. RT-PCR analyses demonstrated expression of the AWAK gene in the chicken intestine.
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