Nanomolar E-Selectin Antagonists with Prolonged Half-Lives by a Fragment-Based Approach
摘要:
Selectins, a family of C-type lectins, play a key role in inflammatory diseases (e.g., asthma and arthritis). However, the only millimolar affinity of sialyl Lewis(x) (sLe(x)), which is the common tetrasaccharide epitope of all physiological selectin ligands, has been a major obstacle to the development of selectin antagonists for therapeutic applications. In a fragment-based approach guided by NMR, ligands binding to a second site in close proximity to a sLe(x) mimic were identified. A library of antagonists obtained by connecting the sLe(x) mimic to the best second-site ligand via triazole linkers of different lengths was evaluated by surface plasmon resonance. Detailed analysis of the five most promising candidates revealed antagonists with K-D values ranging from 30 to 89 nM. In contrast to carbohydratelectin complexes with typical half-lives (t(1/2)) in the range of one second or even less, these fragment-based selectin antagonists show t(1/2) of several minutes. They exhibit a promising starting point for the development of novel anti-inflammatory drugs.
Exploiting translational stalling peptides in an effort to extend azithromycin interaction within the prokaryotic ribosome nascent peptide exit tunnel
作者:Arren Z. Washington、Subhasish Tapadar、Alex George、Adegboyega K. Oyelere
DOI:10.1016/j.bmc.2015.04.078
日期:2015.8
The ribosome is the primary protein synthesis machine in the cell and is a target for treatment of a variety of diseases including bacterial infection and cancer. The ribosomal peptide exit tunnel, the route of egress for the nascent peptide, is an inviting site for drug design. Toward a rational engagement of the nascent peptide components for the design of small molecule inhibitors of ribosome function, we designed and disclosed herein a set of N-10 indole functionalized azithromycin analogs. The indole moiety of these compounds is designed to mimic the translation stalling interaction of SecM W155 side-chain with the prokaryotic (Escherichia coli) ribosome A751 residue. Many of these N-10 functionalized compounds have enhanced translation inhibition activities against E. coli ribosome relative to azithromycin while a subset inhibited the growth of representative susceptible bacteria strains to about the same extent as azithromycin. Moreover, the inclusion of bovine serum in the bacterial growth media enhanced the anti-bacterial potency of the N-10 functionalized azithromycin analogs by as high as 10-fold. Published by Elsevier Ltd.