Identification and physical characterization of a spontaneous mutation of the tobacco mosaic virus in the laboratory environment

• Published in: Scientific reports Vol. 11; no. 1; pp. 15109 - 10
• Main Authors: Lumata, Jenica L., Ball, Darby, Shahrivarkevishahi, Arezoo, Luzuriaga, Michael A., Herbert, Fabian C., Brohlin, Olivia, Lee, Hamilton, Hagge, Laurel M., D’Arcy, Sheena, Gassensmith, Jeremiah J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23-07-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 631/45; 631/45/475; 639/638/45/612; 639/638/45/612/1256; Biotechnology; Capsid - metabolism; Coat protein; Drug delivery; Electrophoretic mobility; Gel electrophoresis; Humanities and Social Sciences; Immunoassays; Ionization; Laboratories; Mass spectrometry; Mass spectroscopy; multidisciplinary; Mutagenesis - genetics; Mutants; Mutation; Mutation - genetics; Point mutation; Proteomics - methods; RNA viruses; RNA, Viral - genetics; Science; Science (multidisciplinary); Serine; Sodium lauryl sulfate; Surface chemistry; Tobacco Mosaic Virus - genetics; Transmission electron microscopy; Tyrosine; Vaccine development; Virus Replication - genetics; Virus-like particles
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-94561-2

Virus-like particles are an emerging class of nano-biotechnology with the Tobacco Mosaic Virus (TMV) having found a wide range of applications in imaging, drug delivery, and vaccine development. TMV is typically produced
in planta
, and, as an RNA virus, is highly susceptible to natural mutation that may impact its properties. Over the course of 2 years, from 2018 until 2020, our laboratory followed a spontaneous point mutation in the TMV coat protein—first observed as a 30 Da difference in electrospray ionization mass spectrometry (ESI–MS). The mutation would have been difficult to notice by electrophoretic mobility in agarose or SDS-PAGE and does not alter viral morphology as assessed by transmission electron microscopy. The mutation responsible for the 30 Da difference between the wild-type (wTMV) and mutant (mTMV) coat proteins was identified by a bottom-up proteomic approach as a change from glycine to serine at position 155 based on collision-induced dissociation data. Since residue 155 is located on the outer surface of the TMV rod, it is feasible that the mutation alters TMV surface chemistry. However, enzyme-linked immunosorbent assays found no difference in binding between mTMV and wTMV. Functionalization of a nearby residue, tyrosine 139, with diazonium salt, also appears unaffected. Overall, this study highlights the necessity of standard workflows to quality-control viral stocks. We suggest that ESI–MS is a straightforward and low-cost way to identify emerging mutants in coat proteins.