Early Events in Amyloid Formation by Lysozyme Detected by Microfluidic Modulation Spectroscopy

The self-assembly of lysozyme to form amyloid fibrils is associated with systemic amyloidosis, a disease characterized by the presence of amyloid deposits in various organs of the body. The early events associated in the self-assembly of lysozyme are not well understood. In this work, we used Microfluidic Modulation Spectroscopy (MMS) to characterize the early events in the self-assembly of human lysozyme. Through MMS, we were able to probe the mid-IR absorption band of the protein which is sensitive to both α-helix and β-structure. With heating at 60 ˚C, the β-turn content of the protein increases while its α-helical content decreases. This result suggests that the first structural transition in the self-assembly of human lysozyme is an α-helix to β-structure conformational rearrangement.