Asor Roi, Khaykelson Daniel, Ben-Nun-Shaul Orly, Oppenheim Ariella, Raviv Uri
Institute of Chemistry and Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem 9190401, Israel.
Department of Haematology, The Hebrew University-Hadassah Medical School, Ein Karem, Jerusalem 91120, Israel.
ACS Omega. 2019 Jan 31;4(1):58-64. doi: 10.1021/acsomega.8b02753. Epub 2019 Jan 2.
Multivalent ions affect the structure and organization of virus nanoparticles. Wild-type simian virus 40 (wt SV40) is a nonenveloped virus belonging to the polyomavirus family, whose external diameter is 48.4 nm. Calcium ions and disulfide bonds are involved in the stabilization of its capsid and are playing a role in its assembly and disassembly pathways. Using solution small-angle X-ray scattering (SAXS), we found that the volume of wt SV40 swelled by about 17% when both of its calcium ions were chelated by ethylene glycol-bis(2-aminoethylether)-,,','-tetraacetic acid and its disulfide bonds were reduced by dithiothreitol. By applying osmotic stress, the swelling could be reversed. DNA-containing virus-like particles behaved in a similar way. The results provide insight into the structural role of calcium ions and disulfide bonds in holding the capsid proteins in compact conformation.
多价离子会影响病毒纳米颗粒的结构和组织。野生型猴病毒40（wt SV40）是一种属于多瘤病毒科的无包膜病毒，其外径为48.4纳米。钙离子和二硫键参与其衣壳的稳定，并在其组装和拆卸途径中发挥作用。通过溶液小角X射线散射（SAXS），我们发现当wt SV40的两个钙离子都被乙二醇双（2-氨基乙醚）-N,N,N',N'-四乙酸螯合且其二硫键被二硫苏糖醇还原时，其体积膨胀了约17%。通过施加渗透压，这种膨胀可以逆转。含DNA的病毒样颗粒表现出类似的行为。这些结果为钙离子和二硫键在使衣壳蛋白保持紧密构象中的结构作用提供了见解。
