Conformational Comparability of Factor IX-Fc Fusion Protein, Factor IX, and Purified Fc Fragment in the Absence and Presence of Calcium
Conformational Comparability of Factor IX-Fc Fusion Protein, Factor IX, and Purified Fc Fragment in the Absence and Presence of Calcium
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DOI：
10.1002/jps.23064
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发表时间：
2012-05-01
影响因子：
3.8
通讯作者：
Berkowitz, Steven A.
中科院分区：
文献类型：
--
作者：
Houde, Damian;Berkowitz, Steven A.
一种长效重组因子IX-Fc融合蛋白(rFIX-Fc)正在开发中，用于治疗血友病B，目前正在进行晚期临床研究。通过限制注射频率和维持疗效，rFIX-FC有望成为血友病B患者的一种新的治疗选择。然而，在获得监管部门的批准之前，除了临床试验外，rFIX-FC还必须经过严格的分析和生物测试。这项测试包括了解这种蛋白质的高阶结构和动力学的需要。在本研究中，我们利用氢/氢交换质谱仪和差示扫描量热法对rFIX-Fc、rFIX和Fc的生物物理性质进行了研究和比较。在这些技术的限制下，我们的结果表明rFIX与rFIX-Fc的固定区存在结构上的相似性。此外，这两种蛋白质在钙结合时的结构和动力学变化也具有很高的可比性。在rFIX-Fc的Fc区和Fc区的情况下，也建立了构象可比性。这些生物物理结果进一步支持这样的结论，即将免疫球蛋白γ1 Fc融合到rFIX不会显著改变FIX或Fc的高阶结构，钙结合到FIX或Fc功能。(C)2012 Wiley期刊，Inc.和美国药剂师协会药学杂志101：1688-1700,2012
A long lasting recombinant factor IX-Fc fusion protein (rFIX-Fc) is being developed for the treatment of hemophilia B and is currently in late stage clinical investigation. By limiting injection frequency and maintaining efficacy, rFIX-Fc shows promise as a new therapeutic option for hemophilia B patients. However, before gaining regulatory approval, rFIX-Fc must undergo rigorous analytical and biological testing, in addition to clinical trials. Included in this testing is the need to understand this protein's higher-order structure and dynamics. In this study, we investigated and compared the biophysical properties of rFIX-Fc, rFIX, and Fc using hydrogen/deuterium exchange mass spectrometry and differential scanning calorimetry. Within the limits of these techniques, our results show that structural comparability exists between rFIX and the FIX region of rFIX-Fc. In addition, changes in the structure and dynamics of both proteins, in response to calcium binding, a requirement for FIX function, are also highly comparable. In the case of Fc and Fc region of rFIX-Fc, conformational comparability is also established. These biophysical results further support the conclusion that fusing an immunoglobulin gamma 1 Fc to rFIX does not significantly alter the higher-order structure of FIX or Fc, Ca binding to FIX, or Fc functionality. (C) 2012 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 101: 1688-1700, 2012