59765-55-8Relevant articles and documents
Large cyclic peptides as cores of multivalent ligands: Application to inhibitors of receptor binding by cholera toxin
Zhang, Zhongsheng,Liu, Jiyun,Verlinde, Christophe L. M. J.,Hol, Wim G. J.,Fan, Erkang
, p. 7737 - 7740 (2004)
Large cyclic decapeptides (up to 50-atom ring) were synthesized efficiently on the solid phase with allylester protection of the carboxyl terminus during elongation. Pentavalent ligands, in a "core-linker-finger" modular setup, were assembled by using these cyclic peptide cores to demonstrate large affinity gains for inhibition of surface receptor binding by the cholera toxin B pentamer. The results suggest that the peptide cores retain expanded conformation in solution so that shorter flexible linkers are needed for larger peptide cores to achieve the best inhibitory results.
Multicolor, one- and two-photon imaging of enzymatic activities in live cells with fluorescently quenched activity-based probes (qABPs)
Hu, Mingyu,Li, Lin,Wu, Hao,Su, Ying,Yang, Peng-Yu,Uttamchandani, Mahesh,Xu, Qing-Hua,Yao, Shao Q.
supporting information; experimental part, p. 12009 - 12020 (2011/09/21)
Fluorescence imaging provides an indispensable way to locate and monitor biological targets within complex and dynamic intracellular environments. Of the various imaging agents currently available, small molecule-based probes provide a powerful tool for live cell imaging, primarily due to their desirable properties, including cell permeability (as a result of their smaller sizes), chemical tractability (e.g., different molecular structures/designs can be installed), and amenability to imaging a wide variety of biological events. With a few exceptions, most existing small molecule probes are however not suitable for in vivo bioimaging experiments in which high-resolution studies of enzyme activity and localization are necessary. In this article, we reported a new class of fluorescently Quenched Activity-Based Probes (qABPs) which are highly modular, and can sensitively image (through multiple enzyme turnovers leading to fluorescence signal amplification) different types of enzyme activities in live mammalian cells with good spatial and temporal resolution. We have also incorporated two-photon dyes into our modular probe design, enabling for the first time activity-based, fluorogenic two-photon imaging of enzyme activities. This, hence, expands the repertoire of smart, responsive probes currently available for live cell bioimaging experiments.
Total synthesis of lysobactin
Guzman-Martinez, Aikomari,Lamer, Ryan,VanNieuwenhze, Michael S.
, p. 6017 - 6021 (2008/02/04)
Antibiotic resistance has become a significant public health concern. Antibiotics that belong to new structural classes and manifest their biological activity via novel mechanisms are urgently needed. Lysobactin, a depsipeptide antibiotic has displayed very strong antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA) as well as vancomycin-resistant enterococci (VRE) with minimum inhibitory concentrations (MICs) ranging from 0.39 to 0.78 μg/mL. The MIC values against VRE were more than 50-fold lower than those reported for vancomycin itself. Lysobactin was found to inhibit nascent peptidoglycan formation; however, this activity was not antagonized in the presence of N-acyl-L-Lys-D-Ala-D-Ala, the binding domain on the cell wall precursors that is utilized by vancomycin. Thus, lysobactin represents a promising agent for the treatment bacterial infections due to resistant pathogens. We describe a convergent synthesis of lysobactin that relies upon a highly efficient macrocyclization reaction to assemble the 28-membered cyclic depsipeptide. This synthesis provides the foundation for further study of the mode of action utilized by lysobactin and its analogues.
