PDF(Pubmed)
Abstract：
MIF is a ubiquitous protein involved in proinflammatory processes, which undergoes an oxidation-driven conformational change to oxidized (ox)MIF. We demonstrate that hypochlorous acid, produced by neutrophil-released myeloperoxidase (MPO) under inflammatory conditions, effectively oxidizes MIF into the oxMIF isoform, which is specifically recognized by the anti-oxMIF therapeutic antibody, ON104. NMR investigation of MIF oxidized by the MPO system revealed increased flexibility throughout the MIF structure, including at several catalytic and allosteric sites. Mass spectrometry of MPO-oxMIF revealed methionines as the primary site of oxidation, whereas Pro2 and Tyr99/100 remained almost unmodified. ELISA, SPR and cell-based assays demonstrated that structural changes caused by MPO-driven oxidation promoted binding of oxMIF to its receptor, CD74, which does not occur with native MIF. These data reveal the environment and modifications that facilitate interactions between MIF and its pro-inflammatory receptor, and a route for therapeutic intervention targeting the oxMIF isoform.
摘要：
MIF是参与促炎过程的一种普遍存在的蛋白质，经历氧化驱动的构象变化为氧化的（ox）MIF。我们证明次氯酸，在炎症条件下由中性粒细胞释放的髓过氧化物酶（MPO）产生，有效地将MIF氧化为oxMIF亚型，它被抗oxMIF治疗性抗体特异性识别，ON104.通过MPO系统氧化的MIF的NMR研究表明，整个MIF结构的灵活性增加，包括在几个催化和变构位点。MPO-oxMIF的质谱显示蛋氨酸是氧化的主要部位，而Pro2和Tyr99/100几乎未修改。ELISA,SPR和基于细胞的测定表明，由MPO驱动的氧化引起的结构变化促进了oxMIF与其受体的结合，CD74，其不会与天然MIF一起发生。这些数据揭示了促进MIF与其促炎受体之间相互作用的环境和修饰，以及靶向oxMIF亚型的治疗干预途径。
