Characterization of Parallel β-Sheets at Interfaces by Chiral Sum Frequency Generation Spectroscopy
Islet Amyloid Polypeptide, Spectrum Analysis
Amylin, Spectrum analysis
Chemical Engineering | Chemistry
Characterization of protein secondary structures at interfaces is still challenging due to the limitations of surface-selective optical techniques. Here, we address the challenge of characterizing parallel β-sheets by combining chiral sum frequency generation (SFG) spectroscopy and computational modeling. We focus on human islet amyloid polypeptide aggregates and a de novo designed short polypeptide at lipid/water and air/glass interfaces. We find that parallel β-sheets adopt distinct orientations at various interfaces and exhibit characteristic chiroptical responses in the amide I and N–H stretch regions. Theoretical analysis indicates that the characteristic chiroptical responses provide valuable information on the symmetry, orientation, and vibrational couplings of parallel β-sheet at interfaces.
Fu, Li; Wang, Zhuguang; Psciuk, Brian; Xiao, Dequan; Batista, Victor; and Yan, Elsa C.Y., "Characterization of Parallel β-Sheets at Interfaces by Chiral Sum Frequency Generation Spectroscopy" (2015). Chemistry and Chemical Engineering Faculty Publications. 13.
Fu, L., Wang, Z., Psciuk, B. T., Xiao, D., Batista, V. S., & Yan, E. C. Y. (2015). Characterization of Parallel β-Sheets at Interfaces by Chiral Sum Frequency Generation Spectroscopy. The Journal of Physical Chemistry Letters, 6(8), 1310–1315.