The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficien...The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficient methods for the preparation of Ub-AMC because the currently available technology is still expensive for scaled-up production. In the present work we report an efficient strategy for total chemical synthesis of Ub-AMC through ligation of peptide hydrazides. Three peptide segments are assembled via N-to-C sequential ligation and the resulting product is converted to Ub-AMC via TCEP-mediated desulfurization. The synthetic Ub-AMC is shown to have expected biological functions throug展开更多
Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to acce...Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to access aBtx and their analogues. Here, we reported a new method for a-bungarotoxin by combining Fmoc-SPPS and peptide hydrazide based ligation strategy. The two-segment ligation method may enable efficient synthesis of aBtx analogues. These synthetic toxin peptides are useful tools for development of imaging or therapeutic reagents.展开更多
TNFR1-associated death domain protein(TRADD)with arginine N-GlcNAcylation is a novel and structurally unique posttranslational modification(PTM)glycoprotein that blocks the formation of death-inducing signaling comple...TNFR1-associated death domain protein(TRADD)with arginine N-GlcNAcylation is a novel and structurally unique posttranslational modification(PTM)glycoprotein that blocks the formation of death-inducing signaling complex(DISC),orchestrating host nuclear factorκB(NF-κB)signaling in entero-pathogenic Escherichia coli(EPEC)-infected cells.This particular glycosylated modification plays an extremely vital role for the effective colonization and pathogenesis of pathogens in the gut.Herein we describe the total synthesis of TRADD death domain(residues 195-312)with arginine235 NGlcNAcylation(Arg-GIcNAc TRADD(195-312)).Two longish peptidyl fragments of the wild-type primary sequence were obtained by robust,microwave-assisted,highly efficient,solid-phase peptide synthesis(SPPS),the N-GlcNAcylated sector was built by total synthesis and attached specifically to resinbound peptide with an unprotected ornithine residue via silver-promoted on-resin guanidinylation,ArgGlcNAc TRADD(195-312)was constructed by hydrazide-based native chemical ligation(NCL).The facile synthetic strategy is expected to be generally applicable for the rapid synthesis of other proteins with Arg-GIcNAc modification and to pave the way for the related chemically biological study.展开更多
基金National Basic Research Program of China (973 program, 2013CB932800)the National Natural Science Foundation of China (NSFC, 31100524 to M.Z., 31170817 for C.T., and 20972148 to L.L.)
文摘The C-terminal conjugate of ubiquitin with 7-amino-4-methylcoumarin （Ub-AMC） is an important probe for fluorescencebased analysis of deubiquitinating enzyme （DUB） activity. It is important to develop more efficient methods for the preparation of Ub-AMC because the currently available technology is still expensive for scaled-up production. In the present work we report an efficient strategy for total chemical synthesis of Ub-AMC through ligation of peptide hydrazides. Three peptide segments are assembled via N-to-C sequential ligation and the resulting product is converted to Ub-AMC via TCEP-mediated desulfurization. The synthetic Ub-AMC is shown to have expected biological functions throug
基金supported by the Science and Technological Fund of Anhui Province for Outstanding Youth(No. 1808085J04)the Innovative Program Development Foundation Hefei Center Physical Science Technology(No. 2017FXCX002)
文摘Nicotinic acetylcholine receptors(nAChRs) play important roles in intercellular communications of nerve cells. α-Bungarotoxins(αBtx) is a moderator for the nAChRs. Chemical synthesis provides a promising way to access aBtx and their analogues. Here, we reported a new method for a-bungarotoxin by combining Fmoc-SPPS and peptide hydrazide based ligation strategy. The two-segment ligation method may enable efficient synthesis of aBtx analogues. These synthetic toxin peptides are useful tools for development of imaging or therapeutic reagents.
基金the National Natural Science Foundation of China (Nos.91849129,21807112)PLA Youth Medical Science and Technology Youth Development Program (No.16QNP086)Foundation of Second Military Medical University (No.2016JS11)
文摘TNFR1-associated death domain protein(TRADD)with arginine N-GlcNAcylation is a novel and structurally unique posttranslational modification(PTM)glycoprotein that blocks the formation of death-inducing signaling complex(DISC),orchestrating host nuclear factorκB(NF-κB)signaling in entero-pathogenic Escherichia coli(EPEC)-infected cells.This particular glycosylated modification plays an extremely vital role for the effective colonization and pathogenesis of pathogens in the gut.Herein we describe the total synthesis of TRADD death domain(residues 195-312)with arginine235 NGlcNAcylation(Arg-GIcNAc TRADD(195-312)).Two longish peptidyl fragments of the wild-type primary sequence were obtained by robust,microwave-assisted,highly efficient,solid-phase peptide synthesis(SPPS),the N-GlcNAcylated sector was built by total synthesis and attached specifically to resinbound peptide with an unprotected ornithine residue via silver-promoted on-resin guanidinylation,ArgGlcNAc TRADD(195-312)was constructed by hydrazide-based native chemical ligation(NCL).The facile synthetic strategy is expected to be generally applicable for the rapid synthesis of other proteins with Arg-GIcNAc modification and to pave the way for the related chemically biological study.
