Human endoplasmic reticulum aminopeptidase 1 (ERAP1) is one of two ER luminal aminopeptidases that participate in the final processing of peptide precursors and generates the N-termini of the MHC class I-restricted ep...Human endoplasmic reticulum aminopeptidase 1 (ERAP1) is one of two ER luminal aminopeptidases that participate in the final processing of peptide precursors and generates the N-termini of the MHC class I-restricted epitopes. In order to investigate the interactions of its binding site with substrate peptides, X-ray crystallographic analyses have been carried out to study structures of ERAP1 regulatory (ERAP1_R) domain in complex with antigenic peptides. Single-chain bimodular constructs with various antigenic peptides linked to the C-terminal end of ERAP1_R domain are designed to facilitate crystallization process of these complexes. These recombinant proteins have been purified and crystalized, and x-ray diffraction data of one crystal have been processed to a resolution of 2.8 . The crystal belongs to the space group P21, with unit cell parameters a =64.2, b = 66.8, c = 66.3 , β = 110.2°. A Refmac-refined omit map reveals a clear density for the antigenic peptide’s carboxylate-end that is in contact with the ERAP1 regulatory domain of neighboring molecule. Thus the single-chain bimodular constructs have provided an expedited approach to study sequence-specific interactions between the ERAP1 regulatory domain and antigen peptide’s C-terminal ends.展开更多
Objectives:To determine the association of Human leukocyte antigen B(HLA‑B)alleles with ankylosing spondylitis and the allelic association of HLAB27 with endoplasmic reticulum aminopeptidase 1(ERAP1)single-nucleotide ...Objectives:To determine the association of Human leukocyte antigen B(HLA‑B)alleles with ankylosing spondylitis and the allelic association of HLAB27 with endoplasmic reticulum aminopeptidase 1(ERAP1)single-nucleotide polymorphism(SNP)rs30187 in patients with ankylosing spondylitis(AS).Methods:We studied 48 consecutively enrolled well-defined AS patients and 48 healthy controls recruited from the outpatient clinic of the rheumatology department of Bangabandhu Sheikh Mujib Medical University(BSMMU),Dhaka,Bangladesh.To genotype HLA-B alleles from peripheral blood DNA,we designed sequence-specific primers for polymerase chain reaction.Sanger's sequencing method was used to detect the ERAP1 rs30187 SNP.The HLA-B allele distributions were compared between cases and controls.To infer an allelic association between HLA-B27 and ERAP1,allele distributions from both loci were compared using cross-tabulations.Chi-squared test or Fisher's exact test was used to quantify the association,and their strength of association was tested by odds ratio(OR)with 95%confidence interval(CI).Results:The frequency of HLA-B27 was found to be higher in AS patients(60.4%)than in healthy controls(8.3%).HLA-B27 allele had an OR of 16.8(95%CI=5.2–54.4)for the development of AS.Overall,4%of AS patients had both HLA-B27 and HLA-B40.No significant association was found between ERAP1 rs30187 SNP and HLA-B27 in patients with AS(OR=1.7,95%CI=0.5–5.6).Conclusions:HLA-B27 was significantly associated with AS in patients in Bangladesh.However,no association between ERAP1 rs30187 SNP and HLA-B27 was observed.展开更多
文摘Human endoplasmic reticulum aminopeptidase 1 (ERAP1) is one of two ER luminal aminopeptidases that participate in the final processing of peptide precursors and generates the N-termini of the MHC class I-restricted epitopes. In order to investigate the interactions of its binding site with substrate peptides, X-ray crystallographic analyses have been carried out to study structures of ERAP1 regulatory (ERAP1_R) domain in complex with antigenic peptides. Single-chain bimodular constructs with various antigenic peptides linked to the C-terminal end of ERAP1_R domain are designed to facilitate crystallization process of these complexes. These recombinant proteins have been purified and crystalized, and x-ray diffraction data of one crystal have been processed to a resolution of 2.8 . The crystal belongs to the space group P21, with unit cell parameters a =64.2, b = 66.8, c = 66.3 , β = 110.2°. A Refmac-refined omit map reveals a clear density for the antigenic peptide’s carboxylate-end that is in contact with the ERAP1 regulatory domain of neighboring molecule. Thus the single-chain bimodular constructs have provided an expedited approach to study sequence-specific interactions between the ERAP1 regulatory domain and antigen peptide’s C-terminal ends.
文摘Objectives:To determine the association of Human leukocyte antigen B(HLA‑B)alleles with ankylosing spondylitis and the allelic association of HLAB27 with endoplasmic reticulum aminopeptidase 1(ERAP1)single-nucleotide polymorphism(SNP)rs30187 in patients with ankylosing spondylitis(AS).Methods:We studied 48 consecutively enrolled well-defined AS patients and 48 healthy controls recruited from the outpatient clinic of the rheumatology department of Bangabandhu Sheikh Mujib Medical University(BSMMU),Dhaka,Bangladesh.To genotype HLA-B alleles from peripheral blood DNA,we designed sequence-specific primers for polymerase chain reaction.Sanger's sequencing method was used to detect the ERAP1 rs30187 SNP.The HLA-B allele distributions were compared between cases and controls.To infer an allelic association between HLA-B27 and ERAP1,allele distributions from both loci were compared using cross-tabulations.Chi-squared test or Fisher's exact test was used to quantify the association,and their strength of association was tested by odds ratio(OR)with 95%confidence interval(CI).Results:The frequency of HLA-B27 was found to be higher in AS patients(60.4%)than in healthy controls(8.3%).HLA-B27 allele had an OR of 16.8(95%CI=5.2–54.4)for the development of AS.Overall,4%of AS patients had both HLA-B27 and HLA-B40.No significant association was found between ERAP1 rs30187 SNP and HLA-B27 in patients with AS(OR=1.7,95%CI=0.5–5.6).Conclusions:HLA-B27 was significantly associated with AS in patients in Bangladesh.However,no association between ERAP1 rs30187 SNP and HLA-B27 was observed.
