Time-Resolved SAXS

Dharan R, Shemesh A, Millgram A, Zalk R, Frank GA, Levi-Kalisman Y, Ringel I, Raviv U. Hierarchical Assembly Pathways of Spermine-Induced Tubulin Conical-Spiral Architectures. ACS Nano [Internet]. 2021;15 (5) :8836–8847. Publisher's Version
Asor R, Schlicksup CJ, Zhao Z, Zlotnick A, Raviv U. Rapidly Forming Early Intermediate Structures Dictate the Pathway of Capsid Assembly. Journal of the American Chemical Society [Internet]. 2020; 142 (17) :7868–7882. Publisher's Version
Asor R, Khaykelson D, Ben-nun-Shaul O, Levi-Kalisman Y, Oppenheim A, Raviv U. pH Stability and Disassembly Mechanism of Wild-Type Simian Virus 40. Soft Matter [Internet]. 2020;16 (11) :2803-2814. Publisher's VersionAbstract

Virus are remarkable self-assembled nanobiomaterial-based machines, exposed to a wide range of pH values. Extreme pH values can induce dramatic structural changes, critical for the function of the virus nanoparticles including assembly and genome uncoating. Tuning cargo - capsid interactions is essential for designing viral-based delivery systems. Here we show how pH controls the structure and activity of wild-type simian virus 40 (wtSV40) and the interplay between its cargo and capsid. Using cryo-TEM and solution X-ray scattering, we found that wtSV40 was stable between pH 5.5 and 9, and only slightly swelled with increasing pH. At pH 3, the particles aggregated, while capsid protein pentamers continued to coat the virus cargo but lost their positional correlations. Infectivity was only partly lost after the particles had been returned to pH 7. At pH 10 or higher, the particles were unstable, lost their infectivity, and disassembled. Using time-resolved experiments we discovered that disassembly began by swelling of the particles, poking a hole in the capsid through which the genetic cargo escaped, and followed by a slight shrinking of the capsids and complete disassembly. These findings provide insight into the fundamental intermolecular forces, essential for SV40 function, and for designing virus-based nanobiomaterials, including delivery systems and antiviral drugs.

Dharan R, Shemesh A, Millgram A, Levi-Kalisman Y, Ringel I, Raviv U. Hierarchical Assembly Pathways of Spermine Induced Tubulin Conical-Spiral Architectures. [Internet]. 2019. Publisher's Version
Shemesh A, Ginsburg A, Levi-Kalisman Y, Ringel I, Raviv U. Structure, Assembly, and Disassembly of Tubulin Single Rings. Biochemistry [Internet]. 2018;57 (43) :6153-6165. Publisher's Version
Ojeda-Lopez MA, Needleman DJ, Song C, Ginsburg A, Kohl PA, Li Y, Miller HP, Wilson L, Raviv U, Choi MC. Transformation of taxol-stabilized microtubules into inverted tubulin tubules triggered by a tubulin conformation switch. Nature materials [Internet]. 2014;13 (2) :195. Publisher's Version
Kler S, Asor R, Li C, Ginsburg A, Harries D, Oppenheim A, Zlotnick A, Raviv U. RNA encapsidation by SV40-derived nanoparticles follows a rapid two-state mechanism. Journal of the American Chemical Society [Internet]. 2012;134 (21) :8823-8830. Publisher's Version
Nadler M, Steiner A, Dvir T, Szekely O, Szekely P, Ginsburg A, Asor R, Resh R, Tamburu C, Peres M. Following the structural changes during zinc-induced crystallization of charged membranes using time-resolved solution X-ray scattering. Soft Matter [Internet]. 2011;7 (4) :1512-1523. Publisher's Version