Title
Direct Evidence of Intrinsic Blue Fluorescence from Oligomeric Interfaces of Human Serum Albumin
Author
Arpan Bhattacharya, Soumitra Bhowmik, Amit K. Singh, Prashant Kodgire, Apurba K. Das, Tushar Kanti Mukherjee
Year
2017
Journal
Langmuir
Abstract
The molecular origin behind the concentration-dependent intrinsic blue fluorescence of human serum albumin (HSA) is not known yet. This unusual blue fluorescence is believed to be a characteristic feature of amyloid-like fibrils of protein/peptide and originates due to the delocalization of peptide bond electrons through the extended hydrogen bond networks of cross-β-sheet structure. Herein, by combining the results of spectroscopy, size exclusion chromatography, native gel electrophoresis, and confocal microscopy, we have shown that the intrinsic blue fluorescence of HSA exclusively originates from oligomeric interfaces devoid of any amyloid-like fibrillar structure. Our study suggests that this low energy fluorescence band is not due to any particular residue/sequence, but rather it is a common feature of self-assembled peptide bonds. The present findings of intrinsic blue fluorescence from oligomeric interfaces pave the way for future applications of this unique visual phenomenon for early stage detection of various protein aggregation related human diseases.
Instrument
J-815
Keywords
Circular dichroism, Secondary structure, Biochemistry