Sa. Overman et Gj. Thomas, NOVEL VIBRATIONAL ASSIGNMENTS FOR PROTEINS FROM RAMAN-SPECTRA OF VIRUSES, Journal of Raman spectroscopy, 29(1), 1998, pp. 23-29
Raman spectroscopy and ultraviolet resonance Raman spectroscopy are ve
rsatile methods for probing details of protein structure and dynamics
in complex biological assemblies, including viruses. The information c
ontained in the Raman spectrum of a virus is ordinarily interpreted on
the basis of an understanding that has been developed from detailed s
pectroscopic investigations of simpler and better characterized molecu
lar structures, such as small globular proteins, peptides and related
model compounds and their isotopic derivatives. The model systems appr
oach serves generally as the foundation for reliable band assignments
and has been the key to successful application of Raman methods to sup
ramolecular assemblies. However, the converse approach is also possibl
e. The supramolecular assembly may serve as a 'model compound' and its
Raman signature may provide novel spectra-structure correlations appl
icable to isolated protein subunits, simpler proteins or related small
molecules. Thus, the Raman spectrum of a virus particle can yield new
insights into protein vibrational assignments. Here, a number of new
vibrational assignments that have emerged from Raman studies of filame
ntous viruses are identified. The Raman bands in question have not bee
n identified previously in proteins and are demonstrated to originate
either from vibrations of the protein main-chain (C alpha H marker, 13
40-1350 cm(-1)) or from aromatic amino acid side chains (phenylalanine
marker, 827 cm(-1); tyrosine singlet, 850-855 cm(-1); tryptophan mark
er, 1560 cm(-1)). The present results, which are considered in the lig
ht of existing correlations between data on Raman spectra and protein
structure, suggest that much remains to be learned about the structura
l significance of protein Raman bands. (C) 1998 John Wiley & Sons, Ltd
.