Characterisation of the single copy trefoil peptides intestinal trefoil factor and pS2 and their ability to form covalent dimers.
A bacterial recombinant expression system was established to produce biologically active rat Intestinal Trefoil Factor (rITF). Characterisation of purified rITF shows that both monomers and dimers can be observed under reducing and non-reducing conditions, respectively. Site-directed mutagenesis studies show that Cys57 is necessary for rITF dimer formation. Samples of human gastrointestinal tissue following biopsy also demonstrated the presence of reducible human pS2 and ITF covalent dimers. Three-dimensional models for pS2 and ITF support the hypothesis that both pS2 and ITF can exist as disulphide-linked dimers in vivo and that any proposed function for these peptides must take dimer formation into account.
Chinery
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Department of Pharmacology, Royal College of Surgeons of England, London, UK.
Bates
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Freemont
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D000595:Amino Acid Sequence; D000818:Animals; D003196:Computer Graphics; D003545:Cysteine / Q000737:chemistry / Q000235:genetics; D004064:Digestive System / Q000378:metabolism; D006133:Growth Substances / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D009077:Mucins; D009124:Muscle Proteins; D016297:Mutagenesis, Site-Directed; D009363:Neoplasm Proteins / Q000737:chemistry / Q000235:genetics*; D009479:Neuropeptides; D010455:Peptides / Q000737:chemistry / Q000235:genetics*; D011506:Proteins; D051381:Rats; D011994:Recombinant Proteins; D017386:Sequence Homology, Amino Acid; D000071163:Trefoil Factor-1; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins
D006133:Growth Substances; D009077:Mucins; D009124:Muscle Proteins; D009363:Neoplasm Proteins; D009479:Neuropeptides; D010455:Peptides; D011506:Proteins; D011994:Recombinant Proteins; C051838:TFF1 protein, human; C099037:TFF3 protein, rat; D000071163:Trefoil Factor-1; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins; D003545:Cysteine