From my understanding (or lack thereof), you do not need any specific modifications to a protein in order to study a specific area in dynamic raman spec. studies (provided that the area(s) of interest are identifiable and show strong enough absorbance/signal). However, more often than not dynamics studies in proteins that monitor specific areas of a protein utilize some form of mutant proteins (some truncated, a residue here and/or there swapped, etc.).
Perhaps, this study of the folded and unfolded states of OmpA may be of use to you http://galileo.ucsd.edu/pdf/sanchez_jpcb_08.pdf
Please let me know if this helps.