The protein alpha-synuclein (AS) is the primary fibrillar component of Lewy 
bodies, the pathological hallmark of Parkinson's disease. Wild-type human AS and 
the three mutant forms linked to Parkinson's disease (A53T, A30P, and E46K) all 
form fibrils through a nucleation-dependent pathway; however, the biophysical 
details of these fibrillation events are not yet well understood. Atomic-level 
structural insight is required in order to elucidate the potential role of AS 
fibrils in Parkinson's disease. Here we show that low temperature acquisition of 
magic-angle spinning NMR spectra of wild type AS fibrils-greatly enhances 
spectral sensitivity, enabling the detection of a substantially larger number of 
spin systems. At 0 +/- 3 degrees C sample temperature, cross polarization (CP) 
experiments yield weak signals. Lower temperature spectra (-40 +/- 3 degrees C) 
demonstrated several times greater signal intensity, an effect further amplified 
in 3D 15N-13C-13C experiments, which are required to perform backbone 
assignments on this sample. Thus 3D experiments enabled assignments of most 
amino acids in the rigid part of the fibril (approximately residues 64 to 94), 
as well as tentative site-specific assignments for T22, V26, A27, Y39, G41, S42, 
H50, V52, A53, T54, V55, V63, A107, I112, and S129. Most of these signals were 
not observed in 2D or 3D spectra at 0 +/- 3 degrees C. Spectra acquired at low 
temperatures therefore permitted more complete chemical shift assignments. 
Observation of the majority of residues in AS fibrils represents an important 
step towards solving the 3D structure.