An integrative approach combining ion mobility mass spectrometry, X-ray crystallography and NMR spectroscopy to study the conformational dynamics of α₁-antitrypsin upon ligand binding

TY - JOUR

T1 - An integrative approach combining ion mobility mass spectrometry, X-ray crystallography and NMR spectroscopy to study the conformational dynamics of α1-antitrypsin upon ligand binding

AU - Nyon, Mun Peak

AU - Prentice, Tanya

AU - Day, Jemma

AU - Kirkpatrick, John

AU - Sivalingam, Ganesh

AU - Levy, Geraldine

AU - Haq, Imran

AU - Irving, James A

AU - Lomas, David A.

AU - Christodoulou, John

AU - Thalassinos, K.

AU - Gooptu, Bibekbrata

PY - 2015/5/26

Y1 - 2015/5/26

N2 - Native mass spectrometry (MS) methods permit the study of multiple protein species within solution equilibria, whilst ion mobility (IM)-MS can report on conformational behaviour of specific states. We used IM-MS to study a conformationally labile protein (α1-antitrypsin) that undergoes pathological polymerisation in the context of point mutations. The folded, native state of the Z variant remains highly polymerogenic in physiological conditions, despite only minor thermodynamic destabilisation relative to the wild-type variant. Various data implicate kinetic instability (conformational lability within a native state ensemble) as the basis of Z α1-antitrypsin polymerogenicity. We show the ability of IM-MS to track such disease-relevant conformational behaviour in detail by studying the effects of peptide binding on α1-antitrypsin conformation and dynamics. IM-MS is therefore an ideal platform for the screening of compounds that result in therapeutically-beneficial kinetic stabilisation of native α1-antitrypsin. Our findings are confirmed with high resolution X-ray crystallographic and NMR spectroscopic studies of the same event, which together dissect structural changes from dynamic effects caused by peptide binding at a residue specific level. IM-MS methods therefore have great potential for further study of biologically-relevant thermodynamic and kinetic instability of proteins and provide rapid and multidimensional characterisation of ligand interactions of therapeutic interest. This article is protected by copyright. All rights reserved.

AB - Native mass spectrometry (MS) methods permit the study of multiple protein species within solution equilibria, whilst ion mobility (IM)-MS can report on conformational behaviour of specific states. We used IM-MS to study a conformationally labile protein (α1-antitrypsin) that undergoes pathological polymerisation in the context of point mutations. The folded, native state of the Z variant remains highly polymerogenic in physiological conditions, despite only minor thermodynamic destabilisation relative to the wild-type variant. Various data implicate kinetic instability (conformational lability within a native state ensemble) as the basis of Z α1-antitrypsin polymerogenicity. We show the ability of IM-MS to track such disease-relevant conformational behaviour in detail by studying the effects of peptide binding on α1-antitrypsin conformation and dynamics. IM-MS is therefore an ideal platform for the screening of compounds that result in therapeutically-beneficial kinetic stabilisation of native α1-antitrypsin. Our findings are confirmed with high resolution X-ray crystallographic and NMR spectroscopic studies of the same event, which together dissect structural changes from dynamic effects caused by peptide binding at a residue specific level. IM-MS methods therefore have great potential for further study of biologically-relevant thermodynamic and kinetic instability of proteins and provide rapid and multidimensional characterisation of ligand interactions of therapeutic interest. This article is protected by copyright. All rights reserved.

U2 - 10.1002/pro.2706

DO - 10.1002/pro.2706

M3 - Article

SN - 0961-8368

JO - Protein Science

JF - Protein Science

ER -