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Publication Abstract from PubMed

Inspired by marine cyanobacterial natural products, we synthesized modified peptides with a central statine-core unit, characteristic for aspartic protease inhibition. A series of tasiamide B analogues inhibited BACE1, a therapeutic target in Alzheimer's disease. We probed the stereospecificity of target engagement and determined additional structure-activity relationships with respect to BACE1 and related aspartic proteases, cathepsins D and E. We cocrystallized selected inhibitors with BACE1 to reveal the structural basis for the activity. Hybrid molecules that combine features of tasiamide B and an isophthalic acid moiety-containing sulfonamide showed nanomolar cellular activity. Compounds were screened in a series of rigorous complementary cell-based assays. We measured secreted APP ectodomain (sAPPbeta), membrane bound carboxyl terminal fragment (CTF), levels of beta-amyloid (Abeta) peptides and selectivity for beta-secretase (BACE1) over gamma-secretase. Prioritized compounds showed reasonable stability in vitro and in vivo, and our most potent inhibitor showed efficacy in reducing Abeta levels in the rodent brain.

Cyanobacterial Peptides as a Prototype for the Design of Potent beta-Secretase Inhibitors and the Development of Selective Chemical Probes for Other Aspartic Proteases.,Liu Y, Zhang W, Li L, Salvador LA, Chen T, Chen W, Felsenstein KM, Ladd TB, Price AR, Golde TE, He J, Xu Y, Li Y, Luesch H J Med Chem. 2012 Dec 13;55(23):10749-65. doi: 10.1021/jm301630s. Epub 2012 Nov, 26. PMID:23181502^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.