title: Effect of nitric oxide on conformational changes of ovalbumin accompanying self-assembly into non-disease-associated fibrils.
abstract: Ovalbumin (OVA), one of the members of the serpin-superfamily, is the major protein in chicken eggs. Many studies have demonstrated the polymerization ability of OVA but the detailed molecular mechanisms demonstrating its conformational changes accompanying fibril formation are still unclear. This study revealed nitric oxide (NO) induced conformational changes and oligomerization of egg white OVA, resulting in polymerized fibrils. Electron microscopic analysis showed that NO treatment to OVA under mild acidic condition resulted in morphological changes, producing structures similar to the long protein fibrils found in egg white. Spectroscopic analysis and mass spectrometry found that NO-treated OVA contains increased number of β-sheet, indicating transition from α-helixes to β-sheets, and S-nitrosylation of OVA cysteine residue 367. Structural modeling showed that S-nitrosocysteine, Cys367NO, is located in the amyloidogenic core region of the C-terminal region, nearby the N-terminal core region where the α-to-β transition is induced. Such results provide a potential mechanism for non-disease-associated fibril formation of OVA.
authors: Division of Electron Microscopic Research, Korea Basic Science Institute, 169-148 Gwahak-ro, Daejeon 305-333, Korea.
authors: Dong-Ju
authors: DJ
authors: You
authors: Department of Microbiology & Molecular Genetics, University of Texas Health Science Center, Houston, TX, USA.
authors: Ju Huck
authors: JH
authors: Lee
authors: Division of Mass Spectrometry Research, Korea Basic Science Institute, 162 Yeongudanji-ro, Ochang, 363-883, Korea.
authors: Jin Young
authors: JY
authors: Kim
authors: Department of Chemistry and Nano Science, Ewha Womans University, 52 Ewhayeodaegil, Seodaemun-gu, Seoul 120-750, Korea. Electronic address: gjjhon@ewha.ac.kr.
authors: Gil-Ja
authors: GJ
authors: Jhon
authors: Division of Electron Microscopic Research, Korea Basic Science Institute, 169-148 Gwahak-ro, Daejeon 305-333, Korea; Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si, Gangwon-do 200-701, Korea. Electronic address: hyunsukjung@kbsi.re.kr.
authors: Hyun Suk
authors: HS
authors: Jung
mesh_terms: D000818:Animals; D002645:Chickens; D004529:Egg White / Q000737:chemistry*; D008958:Models, Molecular; D009569:Nitric Oxide / Q000737:chemistry*; D010047:Ovalbumin / Q000737:chemistry*; D017433:Protein Structure, Secondary
chemical_list: D009569:Nitric Oxide; D010047:Ovalbumin
keywords: Egg white; Electron microscopy; Fibrils; Nitric oxide; Ovalbumin; Protein aggregation