Profiles and Majority Voting-Based Ensemble Method for Protein Secondary Structure Prediction

Machine learning techniques have been widely applied to solve the problem of predicting protein secondary structure from the amino acid sequence. They have gained substantial success in this research area. Many methods have been used including k-Nearest Neighbors (k-NNs), Hidden Markov Models (HMMs), Artificial Neural Networks (ANNs) and Support Vector Machines (SVMs), which have attracted attention recently. Today, the main goal remains to improve the prediction quality of the secondary structure elements. The prediction accuracy has been continuously improved over the years, especially by using hybrid or ensemble methods and incorporating evolutionary information in the form of profiles extracted from alignments of multiple homologous sequences. In this paper, we investigate how best to combine k-NNs, ANNs and Multi-class SVMs (M-SVMs) to improve secondary structure prediction of globular proteins. An ensemble method which combines the outputs of two feed-forward ANNs, k-NN and three M-SVM classifiers has been applied. Ensemble members are combined using two variants of majority voting rule. An heuristic based filter has also been applied to refine the prediction. To investigate how much improvement the general ensemble method can give rather than the individual classifiers that make up the ensemble, we have experimented with the proposed system on the two widely used benchmark datasets RS126 and CB513 using cross-validation tests by including PSI-BLAST position-specific scoring matrix (PSSM) profiles as inputs. The experimental results reveal that the proposed system yields significant performance gains when compared with the best individual classifier

Hidden Markov model and Chapman Kolmogrov for protein structures prediction from images

Protein structure prediction and analysis are more significant for living organs to perfect asses the livingorgan functionalities. Several protein structure prediction methods use neural network (NN). However,the Hidden Markov model is more interpretable and effective for more biological data analysis comparedto the NN. It employs statistical data analysis to enhance the prediction accuracy. The current workproposed a protein prediction approach from protein images based on Hidden Markov Model andChapman Kolmogrov equation. Initially, a preprocessing stage was applied for protein imagesbinarization using Otsu technique in order to convert the protein image into binary matrix. Subsequently,two counting algorithms, namely the Flood fill and Warshall are employed to classify the proteinstructures. Finally, Hidden Markov model and Chapman Kolmogrov equation are applied on the classifiedstructures for predicting the protein structure. The execution time and algorithmic performances aremeasured to evaluate the primary, secondary and tertiary protein structure prediction

In Silico prediction of the Caspase degradome

Ph.DDOCTOR OF PHILOSOPH

Two-stage multi-class support vector machines to protein secondary structure prediction. Pac Symp Biocomput

Bioinformatics techniques to protein secondary structure (PSS) prediction are mostly single-stage approaches in the sense that they predict secondary structures of proteins by taking into account only the contextual information in amino acid sequences. In this paper, we propose two-stage Multi-class Support Vector Machine (MSVM) approach where a MSVM predictor is introduced to the output of the first stage MSVM to capture the sequential relationship among secondary structure elements for the prediction. By using position specific scoring matrices, generated by PSI-BLAST, the two-stage MSVM approach achieves Q3 accuracies of 78.0 % and 76.3 % on the RS126 dataset of 126 nonhomologous globular proteins and the CB396 dataset of 396 nonhomologous proteins, respectively, which are better than the highest scores published on both datasets to date.