1262031-91-3

Upstream product

• 75-77-4 chloro-trimethyl-silane 
• 1262031-90-2 2-hydroxy-2-(2-nitrophenyl)ethyl 4-methylbenzenesulfonate 

Relevant academic research and scientific papers

Traceless purification and desulfurization of tau protein ligation products

We present a novel strategy for the traceless purification and synthetic modification of peptides and proteins obtained by native chemical ligation. The strategy involves immobilization of a photocleavable semisynthetic biotin-protein conjugate on strepta

Mechanistic studies on the substrate-tolerant lanthipeptide synthetase ProcM

Lanthipeptides are a class of post-translationally modified peptide natural products. They contain lanthionine (Lan) and methyllanthionine (MeLan) residues, which generate cross-links and endow the peptides with various biological activities. The mechanism of a highly substrate-tolerant lanthipeptide synthetase, ProcM, was investigated herein. We report a hybrid ligation strategy to prepare a series of substrate analogues designed to address a number of mechanistic questions regarding catalysis by ProcM. The method utilizes expressed protein ligation to generate a C-terminal thioester of the leader peptide of ProcA, the substrate of ProcM. This thioester was ligated with a cysteine derivative that resulted in an alkyne at the C-terminus of the leader peptide. This alkyne in turn was used to conjugate the leader peptides to a variety of synthetic peptides by copper-catalyzed azide-alkyne cycloaddition. Using deuterium-labeled Ser and Thr in the substrate analogues thus prepared, dehydration by ProcM was established to occur from C-to-N-terminus for two different substrates. Cyclization also occurred with a specific order, which depended on the sequence of the substrate peptides. Furthermore, using orthogonal cysteine side-chain protection in the two semisynthetic peptide substrates, we were able to rule out spontaneous non-enzymatic cyclization events to explain the very high substrate tolerance of ProcM. finally, the enzyme was capable of exchanging protons at the α-carbon of MeLan, suggesting that ring formation could be reversible. These findings are discussed in the context of the mechanism of the substrate-tolerant ProcM, which may aid future efforts in lanthipeptide engineering.

Photochemical cleavage of leader peptides

We report a photolabile linker compatible with Fmoc solid phase peptide synthesis and Cu(i)-catalyzed alkyne-azide cycloaddition that allows photochemical cleavage to afford a C-terminal peptide fragment with a native amino terminus.