- Multivalent DNA recognition by self-assembled clusters: deciphering structural effects by fragments screening and evaluation as siRNA vectors
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The identification of low-molecular-weight clusters that effectively complex oligonucleotides of therapeutic interest is of great importance for applications in gene delivery. We recently reported the use of self-assembly processes based on chemoselective ligation in order to generate biomolecular clusters for the multivalent recognition of DNA. Herein, we exploit the modularity of this methodology to perform a one-pot fragments screening of scaffolds and binding groups. Structural parameters affecting DNA binding were observed and hits have been identified by fluorescence displacement and gel electrophoresis assays. Finally, we evaluated the potential of these systems for siRNA transfection. One biomolecular cluster was found to effectively complex and transport a 21-mer siRNA inside MCF7 human breast cancer cells, resulting in a significant knockdown of the target gene.
- Bartolami, Eline,Bessin, Yannick,Bettache, Nadir,Gary-Bobo, Magali,Garcia, Marcel,Dumy, Pascal,Ulrich, Sébastien
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- Fragment Linking and Optimization of Inhibitors of the Aspartic Protease Endothiapepsin: Fragment-Based Drug Design Facilitated by Dynamic Combinatorial Chemistry
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Fragment-based drug design (FBDD) affords active compounds for biological targets. While there are numerous reports on FBDD by fragment growing/optimization, fragment linking has rarely been reported. Dynamic combinatorial chemistry (DCC) has become a powerful hit-identification strategy for biological targets. We report the synergistic combination of fragment linking and DCC to identify inhibitors of the aspartic protease endothiapepsin. Based on X-ray crystal structures of endothiapepsin in complex with fragments, we designed a library of bis-acylhydrazones and used DCC to identify potent inhibitors. The most potent inhibitor exhibits an IC50value of 54 nm, which represents a 240-fold improvement in potency compared to the parent hits. Subsequent X-ray crystallography validated the predicted binding mode, thus demonstrating the efficiency of the combination of fragment linking and DCC as a hit-identification strategy. This approach could be applied to a range of biological targets, and holds the potential to facilitate hit-to-lead optimization.
- Mondal, Milon,Radeva, Nedyalka,Fanlo-Virgós, Hugo,Otto, Sijbren,Klebe, Gerhard,Hirsch, Anna K. H.
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supporting information
p. 9422 - 9426
(2016/08/05)
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- In situ deprotection and incorporation of unnatural amino acids during cell-free protein synthesis
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The S30 extract from E. coli BL21 Star (DE3) used for cell-free protein synthesis removes a wide range of α-amino acid protecting groups by cleaving α-carboxyl hydrazides; methyl, benzyl, tert-butyl, and adamantyl esters; tert-butyl and adamantyl carboxamides; α-amino form-, acet-, trifluoroacet-, and benzamides and sidechain hydrazides and esters. The free amino acids are produced and incorporated into a protein under standard conditions. This approach allows the deprotection of amino acids to be carried out in situ to avoid separate processing steps. The advantages of this approach are demonstrated by the efficient incorporation of the chemically intractable (S)-4-fluoroleucine, (S)-4,5- dehydroleucine, and (2S,3R)-4-chlorovaline into a protein through the direct use of their respective precursors, namely, (S)-4-fluoroleucine hydrazide, (S)-4,5-dehydroleucine hydrazide, and (2S,3R)-4-chlorovaline methyl ester. These results also show that the fluoroand dehydroleucine and the chlorovaline are incorporated into a protein by the normal biosynthetic machinery as substitutes for leucine and isoleucine, respectively. Copyright
- Arthur, Isaac N.,Hennessy, James E.,Padmakshan, Dharshana,Stigers, Dannon J.,Lesturgez, Stéphanie,Fraser, Samuel A.,Liutkus, Mantas,Otting, Gottfried,Oakeshott, John G.,Easton, Christopher J.
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supporting information
p. 6824 - 6830
(2013/06/26)
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- Antihypertensive actions of hydrazidones: Study of acylated dichloroarylhydrazones
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A series of acylated dichloroarylhydrazones has been prepared and evaluated on spontaneously hypertensive rats (SHR). The presence of 2-Cl and 6-Cl aromatic substituents in a clonidine like position is not required since derivatives bearing 2- and 4-chloro as well as 3- and 4-chloro substituents exert antihypertensive activities. Activity is also maintained in certain 2,6 disubstituted derivatives where one of the chlorine atoms is replaced by F or NO2.
- Cave,Galons,Miocque,Rinjard,Tran,Binet
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- Glycine hydrazide as a bifunctional reagent for the synthesis of antigens with steroids as the immunodeterminant groups
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The suitability of glycine hydrazide as a link between steroids and carrier proteins in the synthesis of antigens was examined. Testosterone was used as hapten; bovine serum albumin as carrier protein. The reaction described here of testosterone with glycine hydrazide to form testosterone glycylhydrazone acetate took place under mild conditions and the yield was nearly quantitative. Rabbits immunized with the new antigen developed specific antibodies against testosterone.
- Mueller,Scheuer,Gerdes andMosebach
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p. 1007 - 1009
(2007/10/05)
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