亲环素A抗原表位在三维结构中的初步定位

以抗人亲环素A单克隆抗体D4作捕获抗体，用噬菌体展示库鉴定出亲环素A模拟抗原表位的氨基酸序列为WSLQSFL，在亲环素A的一级结构中没有相同的序列，提示亲环素A抗原表位为构象型的，亲环素A的三维空间结构已测定，利用RasMol等蛋白质三维结构观察软件，可以初步确定亲环素A的抗原表位的时间位置，此抗原表位与环孢素的结合位点有重叠。

Preliminary Determination of the Epitope on 3D-Structure of Cyclophilin A

The phage display peptide library technology was applied to screen the epitope of anti?cyclophilin A monoclonal antibody (D4). After three rounds of biopanning, seven clones of high affinity phages were obtained and the inserts were sequenced. There were three different sequences in the seven inserts. Five clones shared a predominant consensus sequence and the other two were with different sequences. The parallel amino acid sequence (WSLQSFL) of the insert was compared with that of human cyclophilin A. The homologous peptide sequence couldn't be found. This result suggested that the epitope of cyclophilin A was the conformational determinant but not sequential. With the data from PDB database we studied the amino acid residues distribution of the insert on the 3D?structrue of cyclophilin A, and preliminarily determined the epitop on the 3D?structure of cyclophilin A by using the software Rasmol which was typically used to view macromolecule 3D?structure. The epitope partially overlapped the binding site of CyPA to cyclosporin A (CsA).