title: The binding site of bisphenol A to protein disulphide isomerase.
abstract: Protein disulphide isomerase (PDI) has been isolated as a binding protein of bisphenol A (BPA) in the rat brain. In this study, we determined binding sites of BPA to PDI and characterized the binding site. First, we identified the BPA-binding domain with ab, b'a'c, a, b, b' and a'c fragment peptides of PDI by surface plasmon resonance spectroscopy. BPA interacted with ab, b'a 'c, a and b', suggesting that a and b' domains are important in their interaction. Second, ab, b'a'c, a,b,b',a', abb'a', abb', b'a', Δb' and a'c fragment peptides were used for their isomerase activity with RNase as a substrate. BPA could inhibit the activity of peptide fragments including b', suggesting that b' domain contributes to inhibition of catalytic activity of PDI by BPA. Next, we investigated the BPA-binding capacity of PDI by amino acid substitution. PDI lost the BPA-binding activity by the mutation of H258 and mutation of Q245 and N300 also decreased its activity. Furthermore, acidic condition increased the BPA-binding activity of PDI. These results suggest that the charge of these amino acid especially, H258, is important for the BPA to bind to PDI.
authors: Research Center for Environmental Bioscience, Department of Bioscience, School of Science and Technology, Kwansei Gakuin University, Sanda 669-1337, Japan.
authors: Shoko
authors: S
authors: Hashimoto
authors: Keiko
authors: K
authors: Shiomoto
authors: Kazushi
authors: K
authors: Okada
authors: Susumu
authors: S
authors: Imaoka
mesh_terms: D019943:Amino Acid Substitution; D000596:Amino Acids / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001559:Benzhydryl Compounds; D001665:Binding Sites / Q000235:genetics; D055162:Biocatalysis; D002942:Circular Dichroism; D006639:Histidine / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009154:Mutation; D010636:Phenols / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D019704:Protein Disulfide-Isomerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D013816:Thermodynamics; D000098826:Bisphenol A Compounds
chemical_list: D000596:Amino Acids; D001559:Benzhydryl Compounds; D006639:Histidine; D010636:Phenols; D019704:Protein Disulfide-Isomerases; C006780:bisphenol A; D000098826:Bisphenol A Compounds