HLA-B27 subtypes differentially associated with disease exhibit conformational differences in solution.

Human leukocyte antigen (HLA) class I molecules consist of a heavy chain, beta(2)-microglobulin, and a peptide that are noncovalently bound. Certain HLA-B27 subtypes are associated with ankylosing spondylitis (such as HLA-B*2705), whereas others (such as HLA-B*2709) are not. Both differ in only one residue (Asp116 and His116, respectively) in the F pocket that accommodates the peptide C-terminus. An isotope-edited IR spectroscopy study of these HLA-B27 subtypes complexed with the self-peptide RRKWRRWHL was carried out, revealing that the heavy chain is more flexible in the HLA-B*2705 than in the HLA-B*2709 subtype. In agreement with these experimental data, molecular dynamics simulations showed an increased flexibility of the HLA-B*2705 binding groove in comparison with that of the HLA-B*2709 subtype. This difference correlates with an opening of the HLA-B*2705 binding groove, accompanied by a partial detachment of the C-terminal peptide anchor. These combined results demonstrate how the deeply embedded polymorphic heavy-chain residue 116 influences the flexibility of the peptide binding groove in a subtype-dependent manner, a feature that could also influence the recognition of the HLA-B27 complexes by effector cells.

[1]  Ulrike Alexiev,et al.  Differential Peptide Dynamics Is Linked to Major Histocompatibility Complex Polymorphism* , 2004, Journal of Biological Chemistry.

[2]  J. Taurog The mystery of HLA-B27: if it isn't one thing, it's another. , 2007, Arthritis and rheumatism.

[3]  T. Darden,et al.  Particle mesh Ewald: An N⋅log(N) method for Ewald sums in large systems , 1993 .

[4]  Berk Hess,et al.  LINCS: A linear constraint solver for molecular simulations , 1997 .

[5]  D. Naumann,et al.  13C-labeled tyrosine residues as local IR probes for monitoring conformational changes in peptides and proteins. , 2005, Angewandte Chemie.

[6]  G Vriend,et al.  WHAT IF: a molecular modeling and drug design program. , 1990, Journal of molecular graphics.

[7]  A. Gronenborn,et al.  Solvent isotope effect and protein stability , 1995, Nature Structural Biology.

[8]  Rosa Sorrentino,et al.  Dual, HLA-B27 Subtype-dependent Conformation of a Self-peptide , 2004, The Journal of experimental medicine.

[9]  W. L. Jorgensen,et al.  Comparison of simple potential functions for simulating liquid water , 1983 .

[10]  R. Friesner,et al.  Evaluation and Reparametrization of the OPLS-AA Force Field for Proteins via Comparison with Accurate Quantum Chemical Calculations on Peptides† , 2001 .

[11]  D. Madden The three-dimensional structure of peptide-MHC complexes. , 1995, Annual review of immunology.

[12]  M. Fiorillo,et al.  CD8(+) T-cell autoreactivity to an HLA-B27-restricted self-epitope correlates with ankylosing spondylitis. , 2000, The Journal of clinical investigation.

[13]  J. Chalmers,et al.  Handbook of vibrational spectroscopy , 2002 .

[14]  A. Barth,et al.  What vibrations tell about proteins , 2002, Quarterly Reviews of Biophysics.

[15]  H. Mantsch,et al.  New insight into protein secondary structure from resolution-enhanced infrared spectra. , 1988, Biochimica et biophysica acta.

[16]  H. Mantsch,et al.  Determination of protein secondary structure by Fourier transform infrared spectroscopy: a critical assessment. , 1993, Biochemistry.

[17]  D. Rognan,et al.  Mutation of Cys-67 Alters the Thermodynamic Stability of the Human Leukocyte Antigen HLA-B*2705* , 2001, The Journal of Biological Chemistry.

[18]  T. Arakawa,et al.  Conformational changes in G-CSF/Receptor complex as investigated by isotope-edited FTIR spectroscopy. , 1997, Biochemistry.

[19]  M. Vázquez,et al.  HLA-B27: a registry of constitutive peptide ligands. , 2004, Tissue antigens.

[20]  A. Winter,et al.  Natural MHC class I polymorphism controls the pathway of peptide dissociation from HLA-B27 complexes. , 2007, Biophysical journal.

[21]  A. Barth,et al.  The infrared absorption of amino acid side chains. , 2000, Progress in biophysics and molecular biology.

[22]  Werner Mäntele,et al.  Effect of proline to alanine mutation on the thermal stability of the all-beta-sheet protein tendamistat. , 2003, Biochimica et biophysica acta.

[23]  W. Saenger,et al.  Thermodynamic and structural equivalence of two HLA-B27 subtypes complexed with a self-peptide. , 2005, Journal of molecular biology.

[24]  D Rognan,et al.  Use of fluorescence polarization to monitor MHC-peptide interactions in solution. , 2001, Journal of immunological methods.

[25]  P. Parham,et al.  Guilt by association: HLA-B27 and ankylosing spondylitis. , 1990, Immunology today.

[26]  J. Castro HLA-B27 and the Pathogenesis of Spondyloarthropathies , 2007 .

[27]  L. Choo-Smith,et al.  Insight into the secondary structure of non-native proteins bound to a molecular chaperone alpha-crystallin. An isotope-edited infrared spectroscopic study. , 1999, The Journal of biological chemistry.

[28]  Berk Hess,et al.  GROMACS 3.0: a package for molecular simulation and trajectory analysis , 2001 .

[29]  Wolfram Saenger,et al.  HLA-B27 Subtypes Differentially Associated with Disease Exhibit Subtle Structural Alterations* , 2002, The Journal of Biological Chemistry.

[30]  J. Bandekar,et al.  Vibrational spectroscopy and conformation of peptides, polypeptides, and proteins. , 1986, Advances in protein chemistry.

[31]  P. Kollman,et al.  Settle: An analytical version of the SHAKE and RATTLE algorithm for rigid water models , 1992 .

[32]  D. Naumann,et al.  Impact of point mutations on the structure and thermal stability of ribonuclease T1 in aqueous solution probed by Fourier transform infrared spectroscopy. , 1994, Biochemistry.

[33]  J. Mccammon,et al.  On the evaluation and optimization of protein X‐ray structures for pKa calculations , 2003, Protein science : a publication of the Protein Society.

[34]  W. Saenger,et al.  Thermodynamic and Structural Analysis of Peptide- and Allele-dependent Properties of Two HLA-B27 Subtypes Exhibiting Differential Disease Association* , 2004, Journal of Biological Chemistry.

[35]  Werner Mäntele,et al.  Infrared Spectroscopy of Proteins , 2006 .

[36]  A. Marina,et al.  Differential Association of HLA-B*2705 and B*2709 to Ankylosing Spondylitis Correlates with Limited Peptide Subsets but Not with Altered Cell Surface Stability* , 2002, The Journal of Biological Chemistry.

[37]  F. Goñi,et al.  Quantitative studies of the structure of proteins in solution by Fourier-transform infrared spectroscopy. , 1993, Progress in biophysics and molecular biology.

[38]  H. Vogel,et al.  Isotope-edited Fourier transform infrared spectroscopy studies of calmodulin's interaction with its target peptides. , 1994, Biochemistry.

[39]  D Rognan,et al.  Thermodynamic stability of HLA-B*2705. Peptide complexes. Effect of peptide and major histocompatibility complex protein mutations. , 2000, The Journal of biological chemistry.

[40]  C. Carcassi,et al.  Relevance of residue 116 of HLA‐B27 in determining susceptibility to ankylosing spondylitis , 1995, European journal of immunology.

[41]  H. Berendsen,et al.  Molecular dynamics with coupling to an external bath , 1984 .

[42]  J. Mccammon,et al.  Calculating pKa values in enzyme active sites , 2003, Protein science : a publication of the Protein Society.