Using Thioamides To Site-Specifically Interrogate the Dynamics of Hydrogen Bond Formation in β-Sheet Folding
作者:Robert M. Culik、Hyunil Jo、William F. DeGrado、Feng Gai
DOI:10.1021/ja301681v
日期:2012.5.16
Thioamides are sterically almost identical to their oxoamide counterparts, but they are weaker hydrogenbond acceptors. Therefore, thioamide amino acids are excellent candidates for perturbing the energetics of backbone-backbone H-bonds in proteins and hence should be useful in elucidating protein folding mechanisms in a site-specific manner. Herein, we validate this approach by applying it to probe
硫代酰胺与它们的氧代酰胺对应物在空间上几乎相同,但它们是较弱的氢键受体。因此,硫代酰胺氨基酸是扰乱蛋白质中骨架-主链 H 键能量学的极好候选者,因此应该有助于以位点特异性方式阐明蛋白质折叠机制。在这里,我们通过应用它来探测链间 H 键形成在经过充分研究的 β-发夹色氨酸拉链折叠动力学中的动态作用来验证这种方法。我们的结果表明,降低肽的骨架 H 键的强度,除了直接靠近 β 转角的那个,不会改变折叠率,这表明 β-发夹中的大多数天然链间 H 键仅形成在折叠过渡状态之后。
Site Specific Preparation of
<i>N‐</i>
Glycosylated Peptides: Thioamide‐Directed Activation of Aspartate
作者:Ameer B. Taresh、Craig A. Hutton
DOI:10.1002/anie.202210367
日期:2022.10.24
A single-atom (O→S) substitution to introduce a backbone thioamide linkage in a peptide facilitates a AgI-promoted, site-specific generation of Asn N-glycopeptides.
在肽中引入主链硫代酰胺键的单原子 (O→S) 取代促进了 Ag I促进的 Asn N-糖肽的位点特异性生成。
Efficient Site-Specific Incorporation of Thioamides into Peptides on a Solid Support
Designing bioactive peptides containing thioamide functionality to modulate their pharmacological properties has been thwarted so far because of various synthetic challenges. The fast, efficient, and inexpensive synthesis and incorporation of a wide range of thionated amino acids into a growing peptide chain on a solid support is reported using standard Fmoc-based chemistry. The commonly employed methodology is comprehensively investigated and optimized with significant improvements regarding the quantity of reagents and reaction conditions. The utility of the protocol is further demonstrated in the synthesis of dithionated linear and monothionated cyclic peptides, which has been a daunting task.