An antibody that prevents serpin polymerisation acts by inducing a novel allosteric behaviour.

Autor:	Motamedi-Shad N; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Jagger AM; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Liedtke M; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K., Faull SV; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K. Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, U.K., Nanda AS; Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Salvadori E; Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K. London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, U.K. School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, U.K., Wort JL; Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Kay CW; Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K. London Centre for Nanotechnology, 17-19 Gordon Street, London WC1H 0AH, U.K., Heyer-Chauhan N; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Miranda E; Department of Biology and Biotechnologies 'Charles Darwin', Sapienza University of Rome, Rome 00185, Italy., Perez J; Departamento de Biologia Celular, Genetica y Fisiologia, Facultad de Ciencias, Campus Teatinos, Universidad de Malaga, Malaga 29071, Spain., Ordóñez A; Department of Medicine, University of Cambridge, Cambridge Institute for Medical Research, Wellcome Trust/Medical Research Council Building, Hills Road, Cambridge CB2 0XY, U.K., Haq I; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Irving JA; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K., Lomas DA; Centre for Respiratory Biology, UCL Respiratory, University College London, London WC1E 6JF, U.K. Institute of Structural and Molecular Biology/Birkbeck, University of London, London WC1E 7HX, U.K.
Jazyk:	angličtina
Zdroj:	The Biochemical journal [Biochem J] 2016 Oct 01; Vol. 473 (19), pp. 3269-90. Date of Electronic Publication: 2016 Jul 12.
DOI:	10.1042/BCJ20160159
Abstrakt:	Serpins are important regulators of proteolytic pathways with an antiprotease activity that involves a conformational transition from a metastable to a hyperstable state. Certain mutations permit the transition to occur in the absence of a protease; when associated with an intermolecular interaction, this yields linear polymers of hyperstable serpin molecules, which accumulate at the site of synthesis. This is the basis of many pathologies termed the serpinopathies. We have previously identified a monoclonal antibody (mAb4B12) that, in single-chain form, blocks α1-antitrypsin (α1-AT) polymerisation in cells. Here, we describe the structural basis for this activity. The mAb4B12 epitope was found to encompass residues Glu32, Glu39 and His43 on helix A and Leu306 on helix I. This is not a region typically associated with the serpin mechanism of conformational change, and correspondingly the epitope was present in all tested structural forms of the protein. Antibody binding rendered β-sheet A - on the opposite face of the molecule - more liable to adopt an 'open' state, mediated by changes distal to the breach region and proximal to helix F. The allosteric propagation of induced changes through the molecule was evidenced by an increased rate of peptide incorporation and destabilisation of a preformed serpin-enzyme complex following mAb4B12 binding. These data suggest that prematurely shifting the β-sheet A equilibrium towards the 'open' state out of sequence with other changes suppresses polymer formation. This work identifies a region potentially exploitable for a rational design of ligands that is able to dynamically influence α1-AT polymerisation. (© 2016 The Author(s).)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu