Secondary structure and 3D homology modeling of swine leukocyte antigen class 2 (SLA-2) molecules

作者：Gao Feng Shan^*; Xu Chong bo; Long Yi hou; Xia Chun

来源：Immunobiology, 2009, 214(6): 475-482.

DOI：10.1016/j.imbio.2008.11.001

• Secondary structure
• 3D
• SLA-2
• Homology modeling

No information to date is available to elucidate the structure of swine leukocyte antigen class I (SLA-I) molecule which is comprised by a heavy chain of SLA-I non-covalently associated with a light chain, (beta(2)-microglobulin ((beta(2)m) proteins. Presently, one of SLA-I gene SLA-2 and beta(2)m gene were expressed as soluble maltose binding proteins (MBP-proteins) in a pMAL-p2X/Escherichia coli TB1 system and identified by western blotting with anti-MBP polyclonal antibodies. The expressed proteins MBP-SLA-2 and MBP-beta(2)m were purified on amylose affinity columns followed by DEAE-Sepharose. The purified products were cleaved by Factor Xa, respectively, and the interest of proteins SLA-2 and beta(2)m were purified on amylose affinity columns followed by separation from MBP on DEAE-Sepharose. The secondary structures of SLA-2 and beta(2)m were analyzed by circular dichroism (CD) spectrophotometry. The three-dimensional (3D) structure of their peptide-binding domain (PBD) was modeled-based sequence homology. The content of the alpha-helix, beta-sheet, turn, and random coil in the SLA-2 protein were 76, 95, 36, and 67 aa, respectively. In the 98 as of beta(2)m, the contents of the alpha-helix, beta-sheet, turn, and random coil were 0, 45, 8, and 45 aa, respectively. The SLA-2 protein displayed a typical alpha-helix structure while beta(2)m protein displayed a typical beta-sheet structure. Homology modeling of the SLA-2 and beta(2)m proteins demonstrated similarities with the structure of human and mouse MHC (major histocompatibility complex) class I proteins.

• 出版日期2009-6
• 单位大连大学