77826-55-2Relevant articles and documents
Characterization of (Boc-Cys/Sec-NHMe)2 and (Boc-Cys/Sec-OMe)2: Evidence of local conformational difference between disulfide and diselenide
Dolle, Ashwini,Reddy, K. Kasi Amarnath,Gunaga, Shubha Shridhar,Krishnamurthy, Kiran,Senapati, Dillip Kumar,Rana, Abhijit,Sindogi, Kishorkumar,Biswal, Himansu S.,Raghothama, Srinivasarao,Gowd, Konkallu Hanumae
, (2020)
Conformations of disulfide and diselenide were compared in (Boc-Cys/Sec-NHMe)2 and (Boc-Cys/Sec-OMe)2 using X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, density functional theory (DFT), and circular dichroism (CD) spectroscopy. Conformations of disulfide/diselenide in polypeptides are defined based on the sign of side chain torsion angle χ3 (–CH2–S/Se–S/Se–CH2–); negative indicates left-handed and positive indicates right-handed orientation. In the crystals of (Boc-Cys-OMe)2 and (Boc-Sec-OMe)2, the disulfide exhibits a left-handed and the diselenide a right-handed orientation. Characterization of cystine and selenocystine derivatives in solution using 1H-NMR, natural abundant 77Se NMR, 2D-ROESY, and chemical shift analysis coupled to DMSO titration has indicated the symmetrical nature and antiparallel orientation of Cys/Sec residues about the disulfide/diselenide bridges. Structural calculations of cystine and selenocystine derivatives using DFT further support the antiparallel orientation of Cys/Sec residues about disulfide/diselenide. The far-ultraviolet (UV) region CD spectra of cystine and selenocystine derivatives have exhibited the negative Cotton effect (CE) for disulfide and positive for diselenide confirming the difference in the conformational preference of disulfide and diselenide. In the previously reported polymorphic structure of (Boc-Sec-OMe)2, the diselenide has right-handed orientation. In the X-ray structures of disulfide and diselenide analogues of Escherichia coli protein encoded by curli specific gene C (CgsC) retrieved from Protein Databank (PDB), disulfide has left-handed and the diselenide right-handed orientation. The current report provides the evidence for the local conformational difference between a disulfide and a diselenide group under unconstrained conditions, which may be useful for the rational replacement of disulfide by diselenide in polypeptide chains.
Palladium-Catalyzed Carbonylative Synthesis of Aryl Selenoesters Using Formic Acid as an Ex Situ CO Source
Yano De Albuquerque, Danilo,Teixeira, Wystan K. O.,Sacramento, Manoela Do,Alves, Diego,Santi, Claudio,Schwab, Ricardo S.
, p. 595 - 605 (2022/01/12)
A new catalytic protocol for the synthesis of selenoesters from aryl iodides and diaryl diselenides has been developed, where formic acid was employed as an efficient, low-cost, and safe substitute for toxic and gaseous CO. This protocol presents a high functional group tolerance, providing access to a large family of selenoesters in high yields (up to 97%) while operating under mild reaction conditions, and avoids the use of selenol which is difficult to manipulate, easily oxidizes, and has a bad odor. Additionally, this method can be efficiently extended to the synthesis of thioesters with moderate-to-excellent yields, by employing for the first time diorganyl disulfides as precursors.
Expressed Protein Ligation without Intein
Kratch, Kaci C.,Leeuwon, Sunshine Z.,Liu, Wenshe Ray,Morse, Jared S.,Qiao, Yuchen,Wang, Wesley Wei,Wang, Xiaoyan Aria,Xu, Shiqing,Yu, Ge
supporting information, p. 7047 - 7054 (2020/05/14)
Proteins with a functionalized C-terminus such as a C-terminal thioester are key to the synthesis of larger proteins via expressed protein ligation. They are usually made by recombinant fusion to intein. Although powerful, the intein fusion approach suffe
