摘　要：衣原体蛋白酶样活性因子（CPAF）是一种沙眼衣原体蛋白酶，其活性可抑制宿主炎症信号、细胞骨架重塑和中性粒细胞活化等过程。本研究运用生物信息学方法对CPAF蛋白的理化性质、亲/疏水性、信号肽、亚细胞定位、跨膜结构、保守结构域、N-糖基化和磷酸化位点、二级/三级结构、配体结合区域和小分子药物、B/T细胞抗原表位以及相互作用蛋白等进行分析。CPAF由601个氨基酸组成，分子质量为67 252.57 Da，理论等电点为5.68，为不稳定的亲水性蛋白质；含有信号肽，无跨膜区，保守结构域位于3～586位氨基酸序列，属于CPAF超家族，主要分布在细胞质；分别存在1个N-糖基化和53个磷酸化位点，二级结构主要以无规则卷曲和α-螺旋组成，存在14个配体结合位点、20个B细胞抗原表位、4种B细胞构象抗原表位、多个可能的T细胞抗原表位。此外，本文还虚拟筛选出5种潜在的有效小分子化合物，CPAF能与htrA、pbpB、recC等10种其他蛋白发生互作关系。这为深入研究CPAF蛋白在沙眼衣原体发病机制中的重要作用提供了理论依据，使其可能成为疫苗研发和药物治疗的靶点。
关键词：沙眼衣原体；CPAF蛋白；生物信息学；结构；抗原表位
中图分类号：R374                                文献标志码：A                            DOI：10.3969/j.issn.1007-7146.2023.03.008

Abstract: Chlamydial protease-like activity factor (CPAF) is a Chlamydia trachomatis protease, which activity results in dampened host inflammation signaling, cytoskeletal remodeling, and suppressed neutrophil activation. We used series of bioinformatics to analyze and predict CPAF protein, physicochemical properties and hydrophobicity, signal peptide, subcellular localization, transmembrane protein structure, conserved region and N-glycosylation sites and phosphorylation sites, the secondary and tertiary structure, ligand-binding regions and small molecular compounds, B-/T-cell epitopes and the interacting proteins. CPAF, which consist of 601 amino acids, the relative molecular weight is 67 252.57 Da, the theoretical isoelectric point is 5.68. The CPAF protein contains a signal peptide and has non-transmembrane regions. The conserved domain of CPAF protein is located at 3～586 amino acid sequence and belongs to CPAF superfamily. The CPAF protein contains 1 N-glycosylation site and 53 phosphorylation sites. The secondary structure is mainly composed of irregular coiling and α-helix. The CPAF protein contains 14 ligand-binding sites, 20 B-cell epitopes, 4 conformational epitopes and several potential T-cell epitopes, and 5 potentially effective screening small molecule compounds. Meanwhile, CPAF may interact with 10 other proteins including htrA、pbpB、recC and so on. This study provides a theoretical basis for further researching the role of CPAF in the pathogenesis of Chlamydia trachomatis, which could be used as a target for vaccine developments and drug therapies.
Key words: Chlamydia trachomatis; CPAF; bioinformatics; structure; antigenic epitope
（Acta Laser Biology Sinica, 2023, 32(3): 247-258）