. corresponding author
Indian Institute of Technology, Delhi
New Delhi
India
anshul.transcriptase@gmail.com
The property of amyloid formation has been hypothesized to be a generic property of the polypeptide chain. However, the propensities of various polypeptides to undergo amyloidogenesis varies over several orders of magnitude. The non-linear signal analysis technique, Recurrence Quantification Analysis (RQA), has previously been applied to predict these propensities by detecting characteristic patterns arising from the hydrophobicity data of the polypeptide sequence. This study aims to experimentally verify the predictions made by RQA by inducing amyloidogenesis in a randomly selected protein predicted by RQA to have a high propensity for amyloid formation. The protein Bovine Carbonic Anhydrase was incubated in mildly denaturing conditions inducing the association seeking surfaces on the partially unfolded conformers to assemble together and form ordered aggregates. The property of these aggregates were then tested using the traditional Congo Red and Thioflavin-T assays along with fluorescence microscopy, transmission electron microscopy, circular dichroism and proteinase-K digestion experiments. The aggregates were found to possess all the properties ascribed to amyloid fibers. Predictions made by RQA were hence validated and its applicability to the problem of predicting amyloidogenic propensities of polypeptide chains was verified.
. corresponding author