Synthetic 1,2,3-triazole-linked glycoconjugates bind with high affinity to human galectin-3
作者:Marcelo Fiori Marchiori、Dênio Emanuel Pires Souto、Leandro Oliveira Bortot、João Francisco Pereira、Lauro Tatsuo Kubota、Richard D. Cummings、Marcelo Dias-Baruffi、Ivone Carvalho、Vanessa Leiria Campo
DOI:10.1016/j.bmc.2015.04.044
日期:2015.7
This work describes the synthesis of the 1,2,3-triazole amino acid-derived-3-O-galactosides 1-6 and the 1,2,3-triazole di-lactose-derived glycoconjugate 7 as potential galectin-3 inhibitors. The target compounds were synthesized by Cu(I)-catalyzed azide-alkyne cycloaddition reaction ('click chemistry') between the azido-derived amino acids N-3-ThrOBn, N-3-PheOBn, N-3-N-Boc-TrpOBn, N-3-N-Boc-LysOBn, N-3-O-tBu-AspOBn and N-3-L-TyrOH, and the corresponding alkyne-based sugar 3-O-propynyl-GalOMe, as well as by click chemistry reaction between the azido-lactose and 2-propynyl lactose. Surface plasmon resonance (SPR) assays showed that all synthetic glycoconjugates 1-7 bound to galectin-3 with high affinity, but the highest binders were the amino acids-derived glycoconjugates 2 (K-D 7.96 mu M) and 4 (KD 4.56 mu M), and the divalent lactoside 7 (K-D1 0.15 mu M/K-D2 19 mu M). Molecular modeling results were in agreement with SPR assays, since more stable interactions with galectin-3 were identified for glycoconjugates 2, 4 and 7. Regarding compounds 2 and 4, they established specific cation-pi (Arg144) and ionic (Asp148) interactions, whereas glycoconjugate 7 was capable to bridge two independent galectin-3 CRDs, creating a non-covalent cross-link between two monomers and, thus, reaching a submicromolar affinity towards galectin-3. (C) 2015 Elsevier Ltd. All rights reserved.