Title
Analysis of physicochemical and structural properties determining HIV-1 coreceptor usage.
Abstract
The relationship of HIV tropism with disease progression and the recent development of CCR5-blocking drugs underscore the importance of monitoring virus coreceptor usage. As an alternative to costly phenotypic assays, computational methods aim at predicting virus tropism based on the sequence and structure of the V3 loop of the virus gp120 protein. Here we present a numerical descriptor of the V3 loop encoding its physicochemical and structural properties. The descriptor allows for structure-based prediction of HIV tropism and identification of properties of the V3 loop that are crucial for coreceptor usage. Use of the proposed descriptor for prediction results in a statistically significant improvement over the prediction based solely on V3 sequence with 3 percentage points improvement in AUC and 7 percentage points in sensitivity at the specificity of the 11/25 rule (95%). We additionally assessed the predictive power of the new method on clinically derived 'bulk' sequence data and obtained a statistically significant improvement in AUC of 3 percentage points over sequence-based prediction. Furthermore, we demonstrated the capacity of our method to predict therapy outcome by applying it to 53 samples from patients undergoing Maraviroc therapy. The analysis of structural features of the loop informative of tropism indicates the importance of two loop regions and their physicochemical properties. The regions are located on opposite strands of the loop stem and the respective features are predominantly charge-, hydrophobicity- and structure-related. These regions are in close proximity in the bound conformation of the loop potentially forming a site determinant for the coreceptor binding. The method is available via server under http://structure.bioinf.mpi-inf.mpg.de/.
Year
DOI
Venue
2013
10.1371/journal.pcbi.1002977
PLOS COMPUTATIONAL BIOLOGY
Keywords
Field
DocType
protein conformation,tropism,cluster analysis,computer simulation,amino acid sequence,structure activity relationship,support vector machines
Sequence alignment,Tropism,Maraviroc,Biology,HIV tropism,Tissue tropism,Bioinformatics,V3 loop,Genetics,Peptide sequence,Protein structure
Journal
Volume
Issue
ISSN
9
3
1553-734X
Citations 
PageRank 
References 
5
0.58
9
Authors
5
Name
Order
Citations
PageRank
Katarzyna Bozek150.91
Thomas Lengauer23155605.03
Saleta Sierra350.58
Rolf Kaiser421347.27
Francisco S Domingues534018.01