Virus Isoelectric Point Determination Using Single-Particle Chemical Force Microscopy
Virus Isoelectric Point Determination Using Single-Particle Chemical Force Microscopy
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DOI：
10.1021/acs.langmuir.9b03070
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发表时间：
2020-01-14
期刊：
影响因子：
3.9
通讯作者：
Heldt, Caryn L.
中科院分区：
文献类型：
--
作者：
Mi, Xue;Bromley, Emily K.;Heldt, Caryn L.
病毒胶体行为受病毒表面和周围环境的相互作用控制。表征病毒表面电荷的一种方法是等电点（pI）。传统的病毒pI测定集中在病毒溶液的批量表征上。然而，病毒衣壳是极其异质性的，并且单粒子方法可以提供关于在群体中观察到的表面电荷范围的更多信息。测量病毒pI的一种方法是化学力显微镜（CFM）。CFM是一种单粒子技术，用于测量功能化原子力显微镜（AFM）探针的粘附力，在这种情况下，病毒共价结合到表面。使用无包膜猪细小病毒（PPV）和有包膜牛病毒性腹泻病毒（BVDV）证明CFM用于不同表面特性的病毒颗粒。我们已经验证了CFM，以确定PPV的pI为4.8-5.1，文献中已知pI值为5.0，并预测BVDV的未知pI为4.3-4.5。散装测量，zeta电位，和水两相系统（ATPS）交叉分配方法也被用来验证新的CFM方法的病毒pI。大多数方法都很一致。CFM可以在单颗粒水平上检测病毒衣壳的表面电荷，并能够比较不同类型病毒之间的表面电荷。
Virus colloidal behavior is governed by the interaction of the viral surface and the surrounding environment. One method to characterize the virus surface charge is the isoelectric point (pI). Traditional determination of virus pI has focused on the bulk characterization of a viral solution. However, virus capsids are extremely heterogeneous, and a single-particle method may give more information on the range of surface charge observed across a population. One method to measure the virus pI is chemical force microscopy (CFM). CFM is a single-particle technique that measures the adhesion force of a functionalized atomic force microscope (AFM) probe and, in this case, a virus covalently bound to a surface. Non-enveloped porcine parvovirus (PPV) and enveloped bovine viral diarrhea virus (BVDV) were used to demonstrate the use of CFM for viral particles with different surface properties. We have validated the CFM to determine the pI of PPV to be 4.8-5.1, which has a known pI value of 5.0 in the literature, and to predict the unknown pI of BVDV to be 4.3-4.5. Bulk measurements, zeta-potential, and aqueous two-phase system (ATPS) cross-partitioning methods were also used to validate the new CFM method for the virus pI. Most methods were in good agreement. CFM can detect the surface charge of viral capsids at a single-particle level and enable the comparison of surface charge between different types of viruses.