Antimitochondrial Antibody Recognition and Structural Integrity of the Inner Lipoyl Domain of the E2 Subunit of Pyruvate Dehydrogenase Complex

Overview

Journal J Immunol

Specialty Allergy & Immunology

Date 2013 Jul 30

PMID 23894195

Citations 22

Authors

Jinjun Wang

Madhu S Budamagunta

John C Voss

Mark J Kurth

Kit S Lam

Ling Lu

Thomas P Kenny

Christopher Bowlus

Kentaro Kikuchi

Ross L Coppel

Aftab A Ansari

M Eric Gershwin

Patrick S C Leung

Affiliations

Soon will be listed here.

Abstract

Antimitochondrial autoantibodies (AMAs), the serological hallmark of primary biliary cirrhosis, are directed against the lipoyl domain of the E2 subunit of pyruvate dehydrogenase (PDC-E2). However, comprehensive analysis of the amino acid residues of PDC-E2 lipoyl β-sheet with AMA specificity is lacking. In this study, we postulated that specific residues within the lipoyl domain are critical to AMA recognition by maintaining conformational integrity. We systematically replaced each of 19 residue peptides of the inner lipoyl domain with alanine and analyzed these mutants for reactivities against 60 primary biliary cirrhosis and 103 control sera. Based on these data, we then constructed mutants with two, three, or four replacements and, in addition, probed the structure of the substituted domains using thiol-specific spin labeling and electron paramagnetic resonance (EPR) of a (5)Ile→Ala and (12)Ile→Ala double mutant. Single alanine replacement at (5)Ile, (12)Ile, and (15)Glu significantly reduced AMA recognition. In addition, mutants with two, three, or four replacements at (5)Ile, (12)Ile, and (15)Glu reduced AMA reactivity even further. Indeed, EPR reveals a highly flexible structure within the (5)Ile and (12)Ile double-alanine mutant. Autoreactivity is largely focused on specific residues in the PDC-E2 lipoyl domain critical in maintaining the lipoyl loop conformation necessary for AMA recognition. Collectively, the AMA binding studies and EPR analysis demonstrate the necessity of the lipoyl β-sheet structural conformation in anti-PDC-E2 recognition.

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References

Aziz A, Hess J, Budamagunta M, Fitzgerald P, Voss J . Head and rod 1 interactions in vimentin: identification of contact sites, structure, and changes with phosphorylation using site-directed spin labeling and electron paramagnetic resonance. J Biol Chem. 2009; 284(11):7330-8. PMC: 2652308. DOI: 10.1074/jbc.M809029200. View

Gershwin M, Mackay I . The causes of primary biliary cirrhosis: Convenient and inconvenient truths. Hepatology. 2007; 47(2):737-45. DOI: 10.1002/hep.22042. View

Bogdanos D, Baum H, Vergani D, Burroughs A . The role of E. coli infection in the pathogenesis of primary biliary cirrhosis. Dis Markers. 2011; 29(6):301-11. PMC: 3835537. DOI: 10.3233/DMA-2010-0745. View

Leung P, Chuang D, Wynn R, Cha S, Danner D, Ansari A . Autoantibodies to BCOADC-E2 in patients with primary biliary cirrhosis recognize a conformational epitope. Hepatology. 1995; 22(2):505-13. View

Hess J, Budamagunta M, Aziz A, Fitzgerald P, Voss J . Electron paramagnetic resonance analysis of the vimentin tail domain reveals points of order in a largely disordered region and conformational adaptation upon filament assembly. Protein Sci. 2012; 22(1):47-55. PMC: 3575859. DOI: 10.1002/pro.2182. View

Chen H, Liu Z, Meyer-Franke A, Brodbeck J, Miranda R, McGuire J . Small molecule structure correctors abolish detrimental effects of apolipoprotein E4 in cultured neurons. J Biol Chem. 2011; 287(8):5253-66. PMC: 3285306. DOI: 10.1074/jbc.M111.276162. View

Benson G, Kikuchi K, Miyakawa H, Tanaka A, Watnik M, Gershwin M . Serial analysis of antimitochondrial antibody in patients with primary biliary cirrhosis. Clin Dev Immunol. 2004; 11(2):129-33. PMC: 2270709. DOI: 10.1080/10446670410001722113. View

Bogdanos D, Baum H, Okamoto M, Montalto P, Sharma U, Rigopoulou E . Primary biliary cirrhosis is characterized by IgG3 antibodies cross-reactive with the major mitochondrial autoepitope and its Lactobacillus mimic. Hepatology. 2005; 42(2):458-65. DOI: 10.1002/hep.20788. View

Acar S, Carlson D, Budamagunta M, Yarov-Yarovoy V, Correia J, Ninonuevo M . The bipolar assembly domain of the mitotic motor kinesin-5. Nat Commun. 2013; 4:1343. PMC: 3562449. DOI: 10.1038/ncomms2348. View

10.

Van de Water J, Gershwin M, Leung P, Ansari A, Coppel R . The autoepitope of the 74-kD mitochondrial autoantigen of primary biliary cirrhosis corresponds to the functional site of dihydrolipoamide acetyltransferase. J Exp Med. 1988; 167(6):1791-9. PMC: 2189671. DOI: 10.1084/jem.167.6.1791. View

11.

Fussey S, Ali S, Guest J, James O, Bassendine M, Yeaman S . Reactivity of primary biliary cirrhosis sera with Escherichia coli dihydrolipoamide acetyltransferase (E2p): characterization of the main immunogenic region. Proc Natl Acad Sci U S A. 1990; 87(10):3987-91. PMC: 54029. DOI: 10.1073/pnas.87.10.3987. View

12.

Cha S, Leung P, Coppel R, Van de Water J, Ansari A, Gershwin M . Heterogeneity of combinatorial human autoantibodies against PDC-E2 and biliary epithelial cells in patients with primary biliary cirrhosis. Hepatology. 1994; 20(3):574-83. View

13.

Bogdanos D, Pusl T, Rust C, Vergani D, Beuers U . Primary biliary cirrhosis following Lactobacillus vaccination for recurrent vaginitis. J Hepatol. 2008; 49(3):466-73. DOI: 10.1016/j.jhep.2008.05.022. View

14.

Howard M, Fuller C, Broadhurst R, Perham R, Tang J, Quinn J . Three-dimensional structure of the major autoantigen in primary biliary cirrhosis. Gastroenterology. 1998; 115(1):139-46. DOI: 10.1016/s0016-5085(98)70375-0. View

15.

Leung P, Rossaro L, Davis P, Park O, Tanaka A, Kikuchi K . Antimitochondrial antibodies in acute liver failure: implications for primary biliary cirrhosis. Hepatology. 2007; 46(5):1436-42. PMC: 3731127. DOI: 10.1002/hep.21828. View

16.

You Z, Wang Q, Bian Z, Liu Y, Han X, Peng Y . The immunopathology of liver granulomas in primary biliary cirrhosis. J Autoimmun. 2012; 39(3):216-21. PMC: 3558985. DOI: 10.1016/j.jaut.2012.05.022. View

17.

Petrlova J, Hong H, Bricarello D, Harishchandra G, Lorigan G, Jin L . A differential association of Apolipoprotein E isoforms with the amyloid-β oligomer in solution. Proteins. 2010; 79(2):402-16. PMC: 3016465. DOI: 10.1002/prot.22891. View

18.

Moteki S, Leung P, Dickson E, Van Thiel D, Galperin C, Buch T . Epitope mapping and reactivity of autoantibodies to the E2 component of 2-oxoglutarate dehydrogenase complex in primary biliary cirrhosis using recombinant 2-oxoglutarate dehydrogenase complex. Hepatology. 1996; 23(3):436-44. DOI: 10.1002/hep.510230307. View

19.

Gershwin M, Mackay I, Sturgess A, Coppel R . Identification and specificity of a cDNA encoding the 70 kd mitochondrial antigen recognized in primary biliary cirrhosis. J Immunol. 1987; 138(10):3525-31. View

20.

Sasaki M, Van de Water J, Kenny T, Gallo M, Leung P, Nakanuma Y . Immunoglobulin gene usage and immunohistochemical characteristics of human monoclonal antibodies to the mitochondrial autoantigens of primary biliary cirrhosis induced in the XenoMouse. Hepatology. 2001; 34(4 Pt 1):631-7. DOI: 10.1053/jhep.2001.27544. View