Premium
Pharmacophore Alignment Search Tool (PhAST): Significance Assessment of Chemical Similarity
Author(s) -
Hähnke Volker,
Rupp Matthias,
Hartmann Alexander K.,
Schneider Gisbert
Publication year - 2013
Publication title -
molecular informatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.481
H-Index - 68
eISSN - 1868-1751
pISSN - 1868-1743
DOI - 10.1002/minf.201300021
Subject(s) - gumbel distribution , markov chain monte carlo , similarity (geometry) , gaussian , sampling (signal processing) , mathematics , monte carlo method , computer science , statistics , data mining , artificial intelligence , chemistry , computational chemistry , extreme value theory , filter (signal processing) , image (mathematics) , computer vision
Previously, we proposed a ligand-based virtual screening technique (PhAST) based on global alignment of linearized interaction patterns. Here, we applied techniques developed for similarity assessment in local sequence alignments to our method resulting in p-values for chemical similarity. We compared two sampling strategies, a simple sampling strategy and a Markov Chain Monte Carlo (MCMC) method, and investigated the similarity of sampled distributions to Gaussian, Gumbel, modified Gumbel, and Gamma distributions. The Gumbel distribution with a Gaussian correction term was identified as the most similar to the observed empirical distributions. These techniques were applied in retrospective screenings on a drug-like dataset. Obtained p-values were adjusted to the size of the screening library with four different methods. Evaluation of E-value thresholds corroborated the Bonferroni correction as a preferred means to identify significant chemical similarity with PhAST. An online version of PhAST with significance estimation is available at http://modlab-cadd.ethz.ch/.