Ganglioside GM3 Analogues Containing Monofluoromethylene-Linked Sialoside: Synthesis, Stereochemical Effects, Conformational Behavior, and Biological Activities.

Glycoconjugates are an important class of biomolecules that regulate numerous biological events in cells. However, these complex, medium-size molecules are metabolically unstable, which hampers detailed investigations of their functions as well as their potential application as pharmaceuticals. Here we report sialidase-resistant analogues of ganglioside GM3 containing a monofluoromethylene linkage instead of the native -sialoside linkage.

CDC25A-inhibitory RE derivatives bind to pocket adjacent to the catalytic site.

RE derivatives, which are cell-permeable and non-electrophilic dual-specificity protein phosphatase inhibitors developed in our laboratory, inhibit CDC25A/B non-competitively, as determined by means of kinetic experiments. To identify the binding site of RE derivatives, we designed and synthesized the new probe molecule RE142, having a Michael acceptor functionality for covalent bond formation with the enzyme, a biotin tag to enable enrichment of probe-bound peptide(s), and a chemically cleavable linker to facilitate release of probe-bound peptides from avidin beads. LC-MS analysis indicated that RE142 binds to one of the residues Cys384-Tyr386 of CDC25A, within a pocket adjacent to the catalytic site.