A practical solid-phase synthesis of Glu7-phalloidin and entry into fluorescent F-actin-binding reagents.
A practical solid-phase synthesis of Glu7-phalloidin and entry into fluorescent F-actin-binding reagents.
复制标题
Glu7-鬼笔环肽的实用固相合成并进入荧光 F-肌动蛋白结合试剂。
DOI：
10.1002/anie.200700017
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Lokey,RScott
中科院分区：
文献类型：
--
作者：
Schuresko,LauraA;Lokey,RScott
Phalloidin (1) is a potent actin-binding toxin whose chemistry and bioactivity have been studied since the early 1900s.[1] Phalloidin binds with high affinity to filamentous actin (F-actin) and lowers the critical concentration of actin polymerization in solution.[2] It has been used extensively to study actin dynamics in vitro, and fluorescent analogues of phalloidin serve as highly specific reagents for microscopic visualization of the actin cytoskeleton.[3] The natural source of phalloidin, Amanita phalloides, is a mushroom that lives in a complex ecological relationship with associated flora and is widely considered to be uncultivable.[1] Thus, an efficient synthetic route to phalloidin would be highly desirable as an alternative source for this reagent and as an entry into related cyclic peptides. Although there have been a number of syntheses of phalloidin analogues both in solution [4–7] and on a solid phase,[8] no synthetic route has been published with yields significant enough to provide this reagent in practical quantities. The yields reported for these syntheses, which relied on the preparation of relatively complex building blocks in solution, ranged from 0.5 [4] to 1.3%.[6, 8] Herein we report an efficient and practical solid-phase synthesis of Glu7-phalloidin (2) in 50% overall yield from simple starting materials. Derivatization of the Glu7 side chain yielded a fluorescent analogue that stains F-actin in fixed cells at a concentration comparable to that of commercial phalloidinbased probes.Phalloidin is a bicyclic heptapeptide which contains an unusual bridging thioether linkage between the Cys and Trp residues. The natural product contains four common l-amino acid residues, a d-threonine residue, an unusual g, d-dihydroxy-l-leucine residue, and the rare cis epimer of 4-hydroxyl-proline. Structure–activity studies have shown that the g, ddihydroxy-l-leucine side chain is not essential for actin binding.[7, 9] We therefore replaced this residue with glutamic acid to provide the derivative 2 with both a handle for linkage to the solid phase and a site for fluorophore attachment. The cis-4-hydroxy-l-proline residue was prepared according to published methods.[8, 10]
