Department of Genetic Engineering Development, Shanghai Fudan-Zhangjiang Bio-pharmaceutical Co., Ltd., Shanghai, China.
PLoS Comput Biol. 2010 Feb 5;6(2):e1000669. doi: 10.1371/journal.pcbi.1000669.
Etanercept, a TNF receptor 2-Fc fusion protein, is currently being used for the treatment of rheumatoid arthritis (RA). However, 25% to 38% of patients show no response which is suspected to be partially due to insufficient affinity of this protein to TNFalpha. By using computational protein design, we found that residue W89 and E92 of TNFR2 were critical for ligand binding. Among several mutants tested, W89Y/E92N displayed 1.49-fold higher neutralizing activity to TNFalpha, as compared to that of Etanercept. Surface plasmon resonance (SPR) based binding assay revealed that the equilibrium dissociation constant of W89Y/E92N to TNFalpha was 3.65-fold higher than that of Etanercept. In a rat model of collagen-induced arthritis (CIA), W89Y/E92N showed a significantly better ability than Etanercept in reducing paw swelling and improvement of arthritic joint histopathologically. These data demonstrate that W89Y/E92N is potentially a better candidate with improved efficacy in treating RA and other autoimmune diseases.
依那西普，一种 TNF 受体 2-Fc 融合蛋白，目前被用于治疗类风湿关节炎（RA）。然而，有 25%到 38%的患者没有反应，这部分原因可能是因为这种蛋白与 TNFalpha 的亲和力不足。通过计算蛋白设计，我们发现 TNFR2 的残基 W89 和 E92 对配体结合至关重要。在测试的几个突变体中，W89Y/E92N 对 TNFalpha 的中和活性比依那西普高 1.49 倍。基于表面等离子体共振（SPR）的结合测定显示，W89Y/E92N 与 TNFalpha 的平衡解离常数比依那西普高 3.65 倍。在胶原诱导的关节炎（CIA）大鼠模型中，W89Y/E92N 在减轻足肿胀和改善关节炎关节组织病理学方面的能力明显优于依那西普。这些数据表明，W89Y/E92N 是一种潜在的更好的候选药物，在治疗 RA 和其他自身免疫性疾病方面具有更好的疗效。
