Thermoresponsive Chiral to Nonchiral Ordering Transformation in the Nematic Liquid-Crystal Phase of Rodlike Viruses: Turning the Survival Strategy of a Virus into Valuable Material Properties

Abstract

The current work investigates the thermoresponsive in situ chiral to nonchiral ordering transformation of a rodlike virus in the naturally assembled state-the chiral nematic liquid crystal (CLC) phase. We take this as an elegant example of reconfigurable self-assembly, through which it is possible to realize in situ transformation from one assembled state to another without disrupting the preformed assembly in general or going through a secondary assembling procedure of the disassembled building blocks. The detailed investigation presented here reveals many unique characteristics of the thermoresponsive 3D chiral ordering of rodlike viruses induced by heat stress. The chiral to nonchiral ordering transformation is highly reversible in the temperature range of up to 60 °C and can be repeated many times. There exists a critical temperature around 40 °C which is independent of the ionic strength and virus concentration. Such reconfigurable ordering in the CLC phase stems from the intrinsic structure change of constituent coat proteins without disrupting the structural integrity of the virus, as revealed by three analytical techniques targeting levels ranging from the molecular, secondary conformation of the constituent proteins to the whole single virus, respectively. Such structural flexibility, also termed polymorphism, is relative to the survival strategies of a biological organism such as the virus and can be transformed into very precious material properties. The potential of the virus-based CLC phase as the chiral matrix to regulate chiro-optical properties of gold nanorods is also presented.

Cholesteric liquid crystals in living matter

“…This behaviour is not understood. A reversible temperaturedriven transition between the cholesteric and nematic states is possible in M13 virus suspensions by heating it above 40 °C and incubating for several days [303].…”

Viral‐based nanomaterials for plasmonic and photonic materials and devices

“…Other plasmon absorption-based sensors have made use of the absorption of circularly polarized light, as opposed to linearly polarized light. For instance, the M13 virus can adopt a chiral nematic liquid crystal phase that can be doped with gold nanorods (AuNRs) to produce a temperature-sensitive platform (Liu et al, 2015). Temperature drives the phase transition between chiral and nonchiral phases, which, combined with the alignment of AuNRs along the phage's long axis via intercalation into the interstitial voids of the chiral structure, produces changes in circular dichroism (CD) absorption (Figure 2c).…”

“…AuNRs are shown to align along the phage main axis and induce changes in circular dichroism absorption upon heating/cooling. (Reprinted with permission from Liu et al (2015). Copyright 2016 Materials Research Society).…”

“…Alignment of AuNRs along the M13 rods in the chiral phase produces circular dichroism absorption which is sensitive to single digit changes in temperature. (Reprinted with permission from Liu et al (2015). Copyright 2015 American Chemical Society).…”

Estudio fisicoquímico del ensamble molecular de la partícula del bacteriófago M13 y mutantes

“…Imágenes a) Se muestran los espectros de fluorescencia intrínseca a diferentes temperaturas de calentamiento y enfriamiento. b) Espectros de dicroísmo circular (DC) a diferentes temperaturas de calentamiento y enfriamiento tomadas de la referencia[40].…”