title: The novel avian protein, AWAK, contains multiple domains with homology to protease inhibitory modules.
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.
authors.affiliation: Institute for Cell and Molecular Biosciences, Kings Walk, University of Newcastle upon Tyne, Newcastle upon Tyne, NE1 7RU, UK.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Nile
authors.forename: Claire L
authors.initials: CL
authors.lastname: Townes
authors.forename: Barry H
authors.initials: BH
authors.lastname: Hirst
authors.forename: Judith
authors.initials: J
authors.lastname: Hall
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification* / Q000494:pharmacology; D002645:Chickens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D018076:DNA, Complementary / Q000235:genetics; D020224:Expressed Sequence Tags; D007413:Intestinal Mucosa / Q000737:chemistry*; D007421:Intestine, Small / Q000737:chemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011480:Protease Inhibitors / Q000737:chemistry; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012486:Salmonella typhimurium / Q000187:drug effects; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D030161:Avian Proteins; D018076:DNA, Complementary; D011480:Protease Inhibitors