Plasmonics-Enhanced Characterization of Cervid PrP (87-114) Fragment Aggregates in Solution

Area of Science:

• Biochemistry
• Biophysics
• Neuroscience

Background:

• The white-tailed deer (WTD) prion protein (PrP) residue 87-114 fragment is implicated in chronic wasting disease (CWD) pathogenesis.
• Understanding the structural conversion of PrP is crucial for CWD transmission research in cervids.

Purpose of the Study:

• To characterize the self-assembled fibrillar aggregates of the WTD PrP (87-114) fragment.
• To investigate peptide aggregation using multimodal characterization techniques under ambient conditions.

Main Methods:

• Utilized plasmon-enhanced bright-field microscopy for imaging.
• Employed label-free surface-enhanced Raman spectroscopy (SERS) for molecular analysis.
• Incorporated Thioflavin T staining to assess fibril formation.

Main Results:

• Observed a transition from dispersed states to well-defined fibrillar networks.
• Detected spectral evolution in backbone-sensitive SERS bands during aggregation.
• Identified amide III and tryptophan vibrational features as indicators of fibrillar architecture in SERS.

Conclusions:

• Established specific SERS spectral features indicative of prion protein fibril formation.
• Provided insights into the aggregation behavior of amyloidogenic sequences relevant to CWD susceptibility.
• Demonstrated the utility of integrated plasmonic substrates for multimodal characterization of protein aggregation.