Unnatural metal‐chelating amino acidsbearing aminodiacetate side‐chains have been introduced into two hexapeptides to obtain efficient lanthanide‐binding peptides. The synthesis of the enantiopure Fmoc‐Adan(tBu)2‐OH synthons is described with overall yields of 32 and 50 % for n=2 and n=3 side‐chain carbon atoms, respectively. The two peptides AcWAdanPGAdanGNH2 (Pn) were synthesized from the protected
带有氨基二乙酸酯侧链的非天然金属螯合氨基酸已被引入两个六肽中,以获得有效的镧系元素结合肽。描述了对映纯Fmoc-Ada n(t Bu)2 -OH合成子的合成,n = 2和n = 3侧链碳原子的总产率分别为32%和50%。通过标准固相肽合成,从受保护的合成子合成了两个肽AcWAda n PGAda n GNH 2(P n)。两种肽P n的镧系元素复合物的研究通过发光滴定,质谱,圆二色性和溶液NMR光谱表明,Ada n链长对络合性能具有显着影响。事实上,挠性化合物P 3点形成单核配合物中等稳定性的(β 11 = 10 9.9),这趋向于转变成一个双核物种在过量的金属离子的存在。有趣的是,更紧密的肽P 2提供了稳定的Ln 3+复合物,并且仅形成了单核Ln P 2加合物。Tb P 2的稳定常数是两个数量级更高(β 11 = 10 12.1)比用于测量的P 3。P 2的La 3+络合物的800 MHz
Synthesis and biological activity of optimized belactosin C congeners
作者:Vadim S. Korotkov、Antje Ludwig、Oleg V. Larionov、Alexander V. Lygin、Michael Groll、Armin de Meijere
DOI:10.1039/c1ob05661a
日期:——
Successful biochemical studies of the natural products belactosin A and C as well as their more stable acylated derivatives have proved them to be powerful proteasome inhibitors and thereby potential candidates as pharmacologically relevant active compounds. In order to understand their structure–biological activity relations in detail and to find ways of improving their biological activity, four new modified belactosin congeners have been synthesized and tested. One of them (compound 6) turned out to be a more potent inhibitor against HeLa cells than the known proteasome inhibitor MG132.
对天然产物贝乳糖素 A 和 C 及其更稳定的酰化衍生物的成功生化研究证明它们是强大的蛋白酶体抑制剂,因此是作为药理学相关活性化合物的潜在候选者。为了详细了解它们的结构-生物活性关系并找到提高其生物活性的方法,合成并测试了四种新的修饰贝乳素同系物。其中一种(化合物 6)被证明是比已知的蛋白酶体抑制剂 MG132 更有效的 HeLa 细胞抑制剂。
Non-proteinogenic amino acids in the pThr-2 position of a pentamer peptide that confer high binding affinity for the polo box domain (PBD) of polo-like kinase 1 (Plk1)
作者:Wen-Jian Qian、Jung-Eun Park、Kyung S. Lee、Terrence R. Burke
DOI:10.1016/j.bmcl.2012.10.093
日期:2012.12
We report herein that incorporating long-chain alkylphenyl-containing non-proteinogenic amino acids in place of His at the pT-2 position of the parent polo-like kinase 1 (Plk1) polo box domain (PBD)-binding pentapeptide, PLHSpT (1a) increases affinity. For certain analogs, approximately two orders-of-magnitude improvement in affinity was observed. Although, none of the new analogs was as potent as our previously described peptide 1b, in which the pT-2 histidine imidazole ring is alkylated at its pi nitrogen (N3), our current finding that the isomeric His(N1)-analog (1c) binds with approximately 50-fold less affinity than 1b, indicates the positional importance of attachment to the His imidazole ring. Our demonstration that a range of modified residues at the pT-2 position can enhance binding affinity, should facilitate the development of minimally-sized Plk1 PBD-binding antagonists. Published by Elsevier Ltd.