Separation of β2-microglobulin conformers by high-field asymmetric waveform ion mobility spectrometry (FAIMS) coupled to electrospray ionisation mass spectrometry

An investigation into the use of high-field asymmetric waveform ion mobility spectrometry (FAIMS) coupled to electrospray ionisation mass spectrometry (ESI-MS) for the differentiation of co-populated protein conformers has been conducted on the amyloidogenic protein β2-microglobulin (β2m). Accumulation of β2m in vivo can result in the deposition of insoluble fibrils whose formation is thought to originate from partially folded protein conformers; hence, the folding properties of β2m are of significant interest. We have analysed β2m using ESI-FAIMS-MS under a range of pH conditions and have studied the effect of the ion mobility spectrometry parameters on the behaviour of the various protein conformers. The data show that different protein conformers can be detected and analysed by ESI-FAIMS-MS, the results being consistent with observations of pH denaturation obtained using complementary biophysical techniques. A variant of β2m with different folding characteristics has been analysed for comparison, and the distinctions observed in the data sets for the two proteins are consistent with their folding behaviour. ESI-FAIMS-MS offers significant opportunities for the study of the conformational properties of proteins and thus may present valuable insights into the roles that different conformers play in diseases related to protein folding. Copyright © 2004 John Wiley & Sons, Ltd.

[1]  S. Radford,et al.  Co-populated Conformational Ensembles of β2-Microglobulin Uncovered Quantitatively by Electrospray Ionization Mass Spectrometry* , 2004, Journal of Biological Chemistry.

[2]  V. Uversky,et al.  Conformational constraints for amyloid fibrillation: the importance of being unfolded. , 2004, Biochimica et biophysica acta.

[3]  A. Corazza,et al.  Properties of Some Variants of Human β2-Microglobulin and Amyloidogenesis* , 2004, Journal of Biological Chemistry.

[4]  J. Kardos,et al.  Increase in the conformational flexibility of β2‐microglobulin upon copper binding: A possible role for copper in dialysis‐related amyloidosis , 2004, Protein science : a publication of the Protein Society.

[5]  D. Selkoe.  Folding proteins in fatal ways , 2003, Nature.

[6]  S. Radford,et al.  A systematic investigation into the effect of protein destabilisation on beta 2-microglobulin amyloid formation. , 2003, Journal of molecular biology.

[7]  S. Radford,et al.  Structural Plasticity and Noncovalent Substrate Binding in the GroEL Apical Domain , 2002, The Journal of Biological Chemistry.

[8]  T. Kawai,et al.  The role of disulfide bond in the amyloidogenic state of β2‐microglobulin studied by heteronuclear NMR , 2002, Protein science : a publication of the Protein Society.

[9]  A. Miranker,et al.  Formation of a copper specific binding site in non-native states of beta-2-microglobulin. , 2002, Biochemistry.

[10]  S. Radford,et al.  Structural properties of an amyloid precursor of β2-microglobulin , 2002, Nature Structural Biology.

[11]  C. Dobson,et al.  A Partially Structured Species of β2-Microglobulin Is Significantly Populated under Physiological Conditions and Involved in Fibrillogenesis* , 2001, The Journal of Biological Chemistry.

[12]  D A Smith,et al.  Beta(2)-microglobulin and its deamidated variant, N17D form amyloid fibrils with a range of morphologies in vitro. , 2001, Journal of molecular biology.

[13]  D. Barnett,et al.  Elongated conformers of charge states +11 to +15 of bovine ubiquitin studied using ESI-FAIMS-MS , 2001, Journal of the American Society for Mass Spectrometry.

[14]  C. Dobson,et al.  Detection of two partially structured species in the folding process of the amyloidogenic protein beta 2-microglobulin. , 2001, Journal of molecular biology.

[15]  D. Barnett,et al.  Investigation of bovine ubiquitin conformers separated by high-field asymmetric waveform ion mobility spectrometry: Cross section measurements using energy-loss experiments with a triple quadrupole mass spectrometer , 2000, Journal of the American Society for Mass Spectrometry.

[16]  S. Radford,et al.  Partially unfolded states of beta(2)-microglobulin and amyloid formation in vitro. , 2000, Biochemistry.

[17]  D. Clemmer,et al.  Anhydrous protein ions. , 1999, Chemical reviews.

[18]  R. Purves,et al.  Electrospray ionization high-field asymmetric waveform ion mobility spectrometry-mass spectrometry. , 1999, Analytical chemistry.

[19]  D. J. Douglas,et al.  Equilibrium unfolding of proteins monitored by electrospray ionization mass spectrometry: distinguishing two-state from multi-state transitions. , 1998, Rapid communications in mass spectrometry : RCM.

[20]  M. Jarrold,et al.  High-resolution ion mobility measurements , 1997 .

[21]  E. G. Nazarov,et al.  A new method of separation of multi-atomic ions by mobility at atmospheric pressure using a high-frequency amplitude-asymmetric strong electric field , 1993 .

[22]  J. Floege,et al.  Clearance and synthesis rates of beta 2-microglobulin in patients undergoing hemodialysis and in normal subjects. , 1991, The Journal of laboratory and clinical medicine.

[23]  C. G. Edmonds,et al.  Solvent-induced conformational changes of polypeptides probed by electrospray-ionization mass spectrometry. , 1991, Rapid communications in mass spectrometry : RCM.

[24]  M. A. Saper,et al.  Structure of the human class I histocompatibility antigen, HLA-A2 , 1987, Nature.

[25]  Igor A Kaltashov,et al.  Studies of biomolecular conformations and conformational dynamics by mass spectrometry. , 2002, Mass spectrometry reviews.

[26]  S. Radford,et al.  Partial unfolding as a precursor to amyloidosis: A discussion of the occurrence, role and implications. , 2001 .