Raman scattering studies of the low-frequency vibrational modes of bacteriophage M13 in water - observation of an axial torsion mode

Low-wavenumber (<= 20 cm(-1)) acoustic vibrations of the M13 phage have been studied using Raman spectroscopy. The dominant acoustic vibrational mode has been found to be at 8.5 cm(-1). The experimental results are compared with theoretical calculations based on an elastic continuum model and appropriate Raman selection rules derived from a bond polarizability model. The observed Raman mode has been shown to belong to one of the Raman-active axial torsion modes of the M13 phage protein coat. It is expected that the detection and characterization of this low-frequency vibrational mode can be used for applications in nanotechnology such as for monitoring the process of virus functionalization and self-assembly.