Molecular Dynamics Simulation Reveals the Selective Binding of Human Leukocyte Antigen Alleles Associated with Behçet's Disease

PLoS One. 2015 Sep 2;10(9):e0135575. doi: 10.1371/journal.pone.0135575. eCollection 2015.

Abstract

Behçet's disease (BD), a multi-organ inflammatory disorder, is associated with the presence of the human leukocyte antigen (HLA) HLA-B*51 allele in many ethnic groups. The possible antigen involvement of the major histocompatibility complex class I chain related gene A transmembrane (MICA-TM) nonapeptide (AAAAAIFVI) has been reported in BD symptomatic patients. This peptide has also been detected in HLA-A*26:01 positive patients. To investigate the link of BD with these two specific HLA alleles, molecular dynamics (MD) simulations were applied on the MICA-TM nonapeptide binding to the two BD-associated HLA alleles in comparison with the two non-BD-associated HLA alleles (B*35:01 and A*11:01). The MD simulations were applied on the four HLA/MICA-TM peptide complexes in aqueous solution. As a result, stabilization for the incoming MICA-TM was found to be predominantly contributed from van der Waals interactions. The P2/P3 residue close to the N-terminal and the P9 residue at the C-terminal of the MICA-TM nonapeptide served as the anchor for the peptide accommodated at the binding groove of the BD associated HLAs. The MM/PBSA free energy calculation predicted a stronger binding of the HLA/peptide complexes for the BD-associated HLA alleles than for the non-BD-associated ones, with a ranked binding strength of B*51:01 > B*35:01 and A*26:01 > A*11:01. Thus, the HLAs associated with BD pathogenesis expose the binding efficiency with the MICA-TM nonapeptide tighter than the non-associated HLA alleles. In addition, the residues 70, 73, 99, 146, 147 and 159 of the two BD-associated HLAs provided the conserved interaction for the MICA-TM peptide binding.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Behcet Syndrome / genetics
  • Behcet Syndrome / immunology*
  • HLA-A Antigens / chemistry
  • HLA-A Antigens / genetics
  • HLA-A Antigens / immunology*
  • HLA-B51 Antigen / chemistry
  • HLA-B51 Antigen / genetics
  • HLA-B51 Antigen / immunology*
  • Histocompatibility Antigens Class I / chemistry
  • Histocompatibility Antigens Class I / immunology*
  • Humans
  • Molecular Dynamics Simulation

Substances

  • HLA-A Antigens
  • HLA-A*26:01 antigen
  • HLA-B51 Antigen
  • Histocompatibility Antigens Class I
  • MHC class I-related chain A

Grants and funding

This work was supported by Asia Research Center fund, Chulalongkorn University. SK thanks the 100th Anniversary Chulalongkorn University Fund for Doctoral Scholarship. PY accepted the Research Grant 2014 from Faculty of Science Ramkhamhaeng University. TR thanks the Thailand Research Fund (IRG5780008). TK, HN and FT received the funding support of Grants-in-Aid for Science Research from the Ministry of Education, Culture, Sport, Science and Technology of Japan (no. 23406031) and were supported by JSPS Bilateral Joint Research Projects. NKa and AM thank the Ratchadaphiseksomphot Endowment Fund from Chulalongkorn University for Postdoctoral fellowship.