%0 Journal Article
%T Design of Thymidine Analogues Targeting Thymidilate Kinase of Mycobacterium tuberculosis
%A Luc Calvin Owono Owono
%A Melalie Keita
%A Eugene Megnassan
%A Vladimir Frecer
%A Stanislav Miertus
%J Tuberculosis Research and Treatment
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/670836
%X We design here new nanomolar antituberculotics, inhibitors of Mycobacterium tuberculosis thymidine monophosphate kinase (TMPKmt), by means of structure-based molecular design. 3D models of TMPKmt-inhibitor complexes have been prepared from the crystal structure of TMPKmt cocrystallized with the natural substrate deoxythymidine monophosphate (dTMP) (1GSI) for a training set of 15 thymidine analogues (TMDs) with known activity to prepare a QSAR model of interaction establishing a correlation between the free energy of complexation and the biological activity. Subsequent validation of the predictability of the model has been performed with a 3D QSAR pharmacophore generation. The structural information derived from the model served to design new subnanomolar thymidine analogues. From molecular modeling investigations, the agreement between free energy of complexation ( ) and values explains 94% of the TMPKmt inhibition ( ) by variation of the computed and 92% for the pharmacophore (PH4) model ( ). The analysis of contributions from active site residues suggested substitution at the 5-position of pyrimidine ring and various groups at the 5¡ä-position of the ribose. The best inhibitor reached a predicted of 0.155£¿nM. The computational approach through the combined use of molecular modeling and PH4 pharmacophore is helpful in targeted drug design, providing valuable information for the synthesis and prediction of activity of novel antituberculotic agents. 1. Introduction A substantial number of the influenza A subtype H1N1 death cases reported by WHO occurred in patients with chronic respiratory conditions shedding light on possible impact of influenza on active tuberculosis (TB) patients [1]. Tuberculosis kills more than 2 million people [2] and infects around 2 billion worldwide [3] with more than 9 million cases annually [4]. According to WHO in the second millennium decade (2020), over 1 billion people will be newly infected and 36 million will die from TB [5, 6] making it a leading cause of mortality as infectious disease. In this regard, the millennium development goal (MDG) to halve by 2015 TB mortality relative to the 1990 level is problematic [7]. First, mortality in comparison with the 1990 level is slightly decreasing but not in Africa [2]. Secondly, the increased occurrence of MDR and XDR-TB strains is disqualifying the current 40-year-old and long-term DOTS drugs: isoniazid, rifampicin, pyrazinamide, and ethambutol [2]. Accordingly the need of new low-cost and short-term anti-TB therapies is more than urgent regardless those currently in the
%U http://www.hindawi.com/journals/trt/2013/670836/