scholarly journals Retraction of ‘Functional dissection of the C-terminal domain of type II DNA topoisomerase from the kinetoplastid hemoflagellate Leishmania donovani’

2021 ◽  
Author(s):  
Tanushri Sengupta ◽  
Mandira Mukherjee ◽  
Chhabinath Mandal ◽  
Aditi Das ◽  
Hemanta K Majumder
Keyword(s):  
Leishmania Donovani ◽  
Type Ii ◽  
Dna Topoisomerase ◽  
Terminal Domain

scholarly journals Characterization of the ATPase activity of topoisomerase II from Leishmania donovani and identification of residues conferring resistance to etoposide

2005 ◽  
Vol 390 (2) ◽  
pp. 419-426 ◽  
Author(s):  
Tanushri Sengupta ◽  
Mandira Mukherjee ◽  
Aditi Das ◽  
Chhabinath Mandal ◽  
Rakhee Das ◽  
...  
Keyword(s):  
Atpase Activity ◽  
Topoisomerase Ii ◽  
Leishmania Donovani ◽  
Binding Pocket ◽  
Dna Topoisomerase ◽  
Terminal Domain ◽  
Specific Selectivity ◽  
Eukaryotic Dna ◽  
First Time

We have cloned and expressed the 43 kDa N-terminal domain of Leishmania donovani topoisomerase II. This protein has an intrinsic ATPase activity and obeys Michaelis–Menten kinetics. Cross-linking studies indicate that the N-terminal domain exists as a dimer both in the presence and absence of nucleotides. Etoposide, an effective antitumour drug, traps eukaryotic DNA topoisomerase II in a covalent complex with DNA. In the present study, we report for the first time that etoposide inhibits the ATPase activity of the recombinant N-terminal domain of L. donovani topoisomerase II. We have modelled the structure of this 43 kDa protein and performed molecular docking analysis with the drug. Mutagenesis of critical amino acids in the vicinity of the ligand-binding pocket reveals less efficient inhibition of the ATPase activity of the enzyme by etoposide. Taken together, these results provide an insight for the development of newer therapeutic agents with specific selectivity.

scholarly journals First total synthesis of the (±)-2-methoxy-6-heptadecynoic acid and related 2-methoxylated analogs as effective inhibitors of the Leishmania topoisomerase IB enzyme

2012 ◽  
Vol 84 (9) ◽  
pp. 1867-1875 ◽  
Author(s):  
Néstor M. Carballeira ◽  
Michelle Cartagena ◽  
Fengyu Li ◽  
Zhongfang Chen ◽  
Christopher F. Prada ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Total Synthesis ◽  
Leishmania Donovani ◽  
Dna Topoisomerase ◽  
Triple Bonds ◽  
Weak Intermolecular Interactions ◽  
Topoisomerase Ib ◽  
Effective Inhibition ◽  
Acetylenic Fatty Acid

The fatty acids (±)-2-methoxy-6Z-heptadecenoic acid, (±)-2-methoxy-6-hepta-decynoic acid, and (±)-2-methoxyheptadecanoic acid were synthesized and their inhibitory activity against the Leishmania DNA topoisomerase IB enzyme (LdTopIB) determined. Both 2-OMe-17:1 fatty acids were synthesized from 4-bromo-1-pentanol, the olefinic fatty acid in 10 steps and in 7 % overall yield, while the acetylenic fatty acid in 7 steps and in 14 % overall yield. The 2-OMe-17:0 acid was prepared in 6 steps and in 42 % yield from 1-hexa-decanol. The 2-OMe-17:1 acids inhibited LdTopIB, with the acetylenic acid displaying an EC50 = 16.6 ± 1.1 μM, but the 2-OMe-17:0 acid did not inhibit LdTopIB. The (±)-2-methoxy-6Z-heptadecenoic acid preferentially inhibited LdTopIB over the human TopIB enzyme. Unsaturation seems to be a prerequisite for effective inhibition, rationalized in terms of weak intermolecular interactions between the active site of LdTopIB and either the double or triple bonds of the fatty acids. Toxicity toward Leishmania donovani promastigotes was also investigated, resulting in the order acetylenic > olefinic > saturated with the (±)-2-methoxy-6-heptadecynoic acid displaying an EC50 = 74.0 ± 17.1 μM. Our results indicate that α-methoxylation decreases the toxicity of C17:1 fatty acids toward L. donovani promastigotes, but improves their selectivity index.

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