Rottlerin dissolves pre-formed protein amyloid: A study on hen egg white lysozyme

Background: Deposition of protein fibrillar aggregates called amyloids in the tissue, is the principal cause of several degenerative diseases. Here, we have shown the disaggregation potential of rottlerin towards hen egg white lysozyme (HEWL) fibrils formed under alkaline conditions (pH-12.2). Methods: Several biophysical methods like Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and fluorescence emission spectra were used for the study. Results and conclusion: Rottlerin exhibited instantaneous disaggregation effect on HEWL fibrils as monitored by Thioflavin T assay, anisotropy study and AFM imaging. Further we have monitored the conformational changes induced by rottlerin on the fibril in terms of surface hydrophobicity and secondary structure through 8-anilino-1-naphthalene sulfonic acid (ANS) fluorescence and FTIR study respectively. We have also attempted to elucidate the type of interaction between HEWL and rottlerin at pH-12.2 employing techniques like quenching study and FTIR. General significance: Rottlerin seems to have potential application as anti-amyloid compound. (C) 2011 Elsevier B.V. All rights reserved.