Victoria Blue B acts as a protein isomerization targeting probe for monitoring lysozyme fibrillation

Abstract

Protein amyloid fibril formation is associated with various human diseases such as Alzheimer’s, Parkinson’s, type II diabetes and Hereditary renal amyloidosis. The mechanism of protein fibrillation and its implication towards these diseases remain vague. It is important to develop probes to monitor the amyloid fibril formation. Although there are similarities between the structures of amyloid proteins, each protein seems to have its own personality. Hence, the development of diverse amyloid-specific probes is not an extravagant demand. In this report, we describe that Victoria Blue B (VBB) can serve as a novel probe for detecting lysozyme fibrillation. Interestingly, VBB emitted red fluorescence upon recognizing lysozyme fiber but did not fluoresce when meeting its native counterpart. The intermolecular force between VBB and lysozyme fibril may be related to electrostatic interaction. The VBB probe not only distinguished amyloids from other non-fiber proteins and exhibited excellent selectivity, but also worked fairly well in the presence of serum or cell extract. Therefore, VBB can serve as a new protein isomerization targeting probe for protein fibrillation.