Application of the Ramanujan Fourier Transform for the Analysis of Secondary Structure Content in Amino Acid Sequences

Abstract

Summary Objective : A novel method is presented for the investigation of protein properties of sequences using Ramanujan Fourier Transform (RFT). Methods : The new methodology involves the preprocessing of protein sequence data by numerically encoding it and then applying the RFT. The RFT is based on projecting the obtained numerical series on a set of basis functions constituted by Ramanujan sums (RS). In RS components, periodicities of finite integer length, rather than frequency, (as in classical harmonic analysis) are considered. Results : The potential of the new approach is documented by a few examples in the analysis of hydrophobic profiles of proteins in two classes including abundance of alpha-helices (group A) or beta-strands (group B). Different patterns are provided as evidence. Conclusions : RFT can be used to characterize the structural properties of proteins and integrate complementary information provided by other signal processing transforms.