Yearley Eric J, Godfrin Paul D, Perevozchikova Tatiana, Zhang Hailiang, Falus Peter, Porcar Lionel, Nagao Michihiro, Curtis Joseph E, Gawande Pradad, Taing Rosalynn, Zarraga Isidro E, Wagner Norman J, Liu Yun
Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland; Department of Chemical and Biomolecular Engineering, Center for Neutron Science, University of Delaware, Newark, Delaware.
Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland; Institute for Research and Applied Physics, University of Maryland, College Park, Maryland.
Biophys J. 2014 Apr 15;106(8):1763-70. doi: 10.1016/j.bpj.2014.02.036.
Monoclonal antibodies (mAbs) are a major class of biopharmaceuticals. It is hypothesized that some concentrated mAb solutions exhibit formation of a solution phase consisting of reversibly self-associated aggregates (or reversible clusters), which is speculated to be responsible for their distinct solution properties. Here, we report direct observation of reversible clusters in concentrated solutions of mAbs using neutron spin echo. Specifically, a stable mAb solution is studied across a transition from dispersed monomers in dilute solution to clustered states at more concentrated conditions, where clusters of a preferred size are observed. Once mAb clusters have formed, their size, in contrast to that observed in typical globular protein solutions, is observed to remain nearly constant over a wide range of concentrations. Our results not only conclusively establish a clear relationship between the undesirable high viscosity of some mAb solutions and the formation of reversible clusters with extended open structures, but also directly observe self-assembled mAb protein clusters of preferred small finite size similar to that in micelle formation that dominate the properties of concentrated mAb solutions.
单克隆抗体（mAb）是生物制药的一个主要类别。据推测，一些浓缩的单克隆抗体溶液会形成由可逆自缔合聚集体（或可逆簇）组成的溶液相，据推测这是其独特溶液性质的原因。在此，我们报告了使用中子自旋回波直接观察单克隆抗体浓缩溶液中的可逆簇。具体而言，研究了一种稳定的单克隆抗体溶液，从稀溶液中的分散单体到更浓缩条件下的簇状状态的转变过程，在此过程中观察到了具有优选尺寸的簇。一旦单克隆抗体簇形成，与典型球状蛋白质溶液中观察到的情况相反，其尺寸在很宽的浓度范围内几乎保持不变。我们的结果不仅确凿地建立了一些单克隆抗体溶液不希望出现的高粘度与具有扩展开放结构的可逆簇形成之间的明确关系，而且还直接观察到了具有优选小有限尺寸的自组装单克隆抗体蛋白质簇，类似于在胶束形成中主导浓缩单克隆抗体溶液性质的簇。
