Cai Yu Chun, Xu Bin, Chu Yan Hong, Yu Ying Fang, Sun Jia Hui, Mo Zi Ran, Yang Han Yin, Yan Shu Ning, Chen Mu Xin, Chen Jia Xu
National Institute of Parasitic Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), Laboratory of Parasite and Vector Biology, Ministry of Public Health, WHO Collaborating Centre for Tropical Diseases, National Center for International Research on Tropical Diseases, Ministry of Science and Technology, Shanghai 200025, China.
National Key Laboratory of Intelligent Tracking and Forecasting for Infectious Diseases, Chinese Center for Disease Control and Prevention (Chinese Center for Tropical Diseases Research), National Institute of Parasitic Diseases, Shanghai 200025, China.
J Trop Med. 2025 Jan 11;2025:8821002. doi: 10.1155/jotm/8821002. eCollection 2025.
Glycosaminoglycan (GAG) molecules on the surface of red blood cells play an important regulatory role in the invasion of merozoites of apicomplexan protozoa. Heparan sulfate, a type of GAG molecule, has been identified as an important receptor facilitating the invasion of red blood cells by these parasites. Proteins in the parasite that exhibit strong affinity for heparin may play a pivotal role in this invasion process. This study aims to use proteomics to identify proteins with high binding affinity to heparin. Bioinformatics was utilized to analyze the subcellular localization and biological functions of these proteins. Candidate genes encoding proteins with strong heparin affinity will be expressed in a prokaryotic system to produce recombinant proteins. The interaction between these recombinant proteins and heparin will be characterized through heparin-binding experiments and other methods. Initially, a mouse model of was established and high-density were obtained. Heparin affinity chromatography was then used to purify natural proteins that can bind to heparin, identifying 186 proteins via ESI-MS that specifically interact with heparin. Further studies were carried out to analyze those specific proteins with unique peptide segments of two or more, yielding 15 proteins, most of which are cell surface proteins and secretory proteins. Based on mass spectrometry identification and subsequent analyses, BMSA5-1-1, peptidyl-prolyl cis-trans isomerase (BmPPIase), and chaperonin were selected for further study due to their potential impact on the invasion of red blood cells by . These candidate proteins were expressed as recombinant proteins using a prokaryotic expression system. In vitro heparin-binding assays demonstrated that these recombinant proteins specifically bind to heparin. Notably, BmPPIase and chaperonin recombinant proteins exhibited activity in specific heparin binding. Molecular interaction studies further confirmed the strong interaction between BmPPIase and heparin. In conclusion, this study used proteomic methods to identify 186 specific proteins with specific binding affinity to heparin, providing in-depth analysis of 15 key proteins. The findings confirmed that BmPPIase and chaperonin specifically bind to heparin, with molecular interaction experiments substantiating the strong interaction between BmPPIase and heparin.
红细胞表面的糖胺聚糖（GAG）分子在顶复门原生动物裂殖子的入侵过程中发挥着重要的调节作用。硫酸乙酰肝素作为一种GAG分子，已被确认为促进这些寄生虫入侵红细胞的重要受体。寄生虫中对肝素具有强亲和力的蛋白质可能在这一入侵过程中起关键作用。本研究旨在利用蛋白质组学技术鉴定与肝素具有高结合亲和力的蛋白质。运用生物信息学分析这些蛋白质的亚细胞定位和生物学功能。编码与肝素具有强亲和力的蛋白质的候选基因将在原核系统中表达以产生重组蛋白。通过肝素结合实验等方法表征这些重组蛋白与肝素之间的相互作用。最初，建立了一个小鼠模型并获得了高密度样本。然后使用肝素亲和色谱法纯化能够结合肝素的天然蛋白质，通过电喷雾电离质谱（ESI-MS）鉴定出186种与肝素特异性相互作用的蛋白质。进一步开展研究分析那些具有两个或更多独特肽段的特定蛋白质，得到了15种蛋白质，其中大多数是细胞表面蛋白和分泌蛋白。基于质谱鉴定及后续分析，由于BMSA5-1-1、肽基脯氨酰顺反异构酶（BmPPIase）和伴侣蛋白可能对疟原虫入侵红细胞有影响，因此选择它们进行进一步研究。使用原核表达系统将这些候选蛋白表达为重组蛋白。体外肝素结合试验表明这些重组蛋白能特异性结合肝素。值得注意的是，BmPPIase和伴侣蛋白重组蛋白在特异性肝素结合中表现出活性。分子相互作用研究进一步证实了BmPPIase与肝素之间的强相互作用。总之，本研究利用蛋白质组学方法鉴定出186种与肝素具有特异性结合亲和力的特定疟原虫蛋白质，对15种关键蛋白质进行了深入分析。研究结果证实BmPPIase和伴侣蛋白能特异性结合肝素，分子相互作用实验证实了BmPPIase与肝素之间的强相互作用。
