Extending Serum Half-life of Albumin by Engineering Neonatal Fc Receptor ( FcRn) Binding
Extending Serum Half-life of Albumin by Engineering Neonatal Fc Receptor ( FcRn) Binding
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DOI：
10.1074/jbc.m114.549832
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发表时间：
2014-05-09
影响因子：
4.8
通讯作者：
Cameron, Jason
中科院分区：
文献类型：
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作者：
Andersen, Jan Terje;Dalhus, Bjorn;Cameron, Jason
背景：FcRN控制白蛋白较长的血清半衰期。结果：白蛋白的单一氨基酸替代显著改善了与FcRN的结合，延长了小鼠和恒河猴的血清半衰期。结论：通过改变FcRN-白蛋白的相互作用，可以调整白蛋白的血清半衰期。意义：本研究报道了一种可改善生物药物血清半衰期的工程白蛋白。许多多肽和蛋白质的治疗面临的一个主要挑战是它们的循环半衰期很短。白蛋白的血清半衰期延长了3周，这是因为它的大小和FcRN介导的循环可以防止细胞内降解，这些特性与免疫球蛋白抗体相同。设计严格依赖于pH的免疫球蛋白-FcRN相互作用可以延长免疫球蛋白的半衰期。然而，白蛋白的这一原理还没有得到广泛的探索。我们通过在C末端引入单点突变来改造人类白蛋白，从而产生了一组与FcRN具有极大提高亲和力的变体。一种亲和力提高12倍的变异体(K573P)在正常小鼠、转人FcRN基因的小鼠和食蟹猴中显示了延长的血清半衰期。重要的是，当单链片段可变抗体在基因上融合到N端或C端时，保持了与FcRN的良好结合。工程白蛋白突变体可能在改善生物药物的血清半衰期方面具有吸引力。
Background: FcRn controls the long serum half-life of albumin. Results: A single amino acid substitution of albumin considerably improved binding to FcRn and extended serum half-life in mice and rhesus monkeys. Conclusion: Serum half-life of albumin may be tailored by engineering the FcRn-albumin interaction. Significance: This study reports on engineered albumin that may be attractive for improving the serum half-life of biopharmaceuticals.A major challenge for the therapeutic use of many peptides and proteins is their short circulatory half-life. Albumin has an extended serum half-life of 3 weeks because of its size and FcRn-mediated recycling that prevents intracellular degradation, properties shared with IgG antibodies. Engineering the strictly pH-dependent IgG-FcRn interaction is known to extend IgG half-life. However, this principle has not been extensively explored for albumin. We have engineered human albumin by introducing single point mutations in the C-terminal end that generated a panel of variants with greatly improved affinities for FcRn. One variant (K573P) with 12-fold improved affinity showed extended serum half-life in normal mice, mice transgenic for human FcRn, and cynomolgus monkeys. Importantly, favorable binding to FcRn was maintained when a single-chain fragment variable antibody was genetically fused to either the N- or the C-terminal end. The engineered albumin variants may be attractive for improving the serum half-life of biopharmaceuticals.