Electronic and Steric Effects on the Rate of the Traceless

Water-soluble phosphinothiols for traceless Staudinger ligation and integration with expressed protein ligation A Tam, MB Soellner, RT Raines Journal of the American Chemical Society 129 (37), 11421-11430 , … Research Summary Dr. Mirna El Khatib … c) Traceless chemical ligations from O acyl serine sites7,10 In this work, the ultimate goal was to examine the feasibility of native chemical ligation (NCL) using serine. Chemical ligation has facilitated the synthesis of large peptides by linking the C-terminus of one … Staudinger Ligation Method for Rapid and Reliable Chemical •Ligation of biological molecules, including amino acids, peptides and protein fragments •Synthesis of peptides and proteins, including the stepwise synthesis of peptides on solid supports KEY BENEFITS •Eliminates need for cysteine residue at the ligation junction •Traceless - leaves no residual atoms in the ligated peptide product

This “fragment condensation” has been achieved in many ways both in solution and by solid-phase peptide synthesis (SPSS) on resin. The most successful method for in-solution coupling is known as native chemical ligation (NCL), and the technique dates back to the pioneering work of Wieland (1953) and subsequently Kent (1994) among many others.

Electronic and Steric Effects on the Rate of the Traceless Notable attributes of this ligation strategy include its ability to generate an amide product without either residual atoms, 3 or racemization, 4 and a high reaction rate. 5 (Diphenylphosphino)methanethiol (1) is the most often used of known reagents for effecting the traceless Staudinger ligation, and has mediated the orthogonal assembly of a Traceless Staudinger Ligation for the Synthesis of WARF reference number P00315US describes a method of using traceless Staudinger ligation for the total chemical synthesis of proteins. Publications Tam A., Soellner M.B. and Raines R.T. 2007. Water-Soluble Phosphinothiols for Traceless Staudinger Ligation and Integration with Expressed Protein Ligation. J. Am. Chem. Soc. 129, 11421–11430.

Traceless synthesis of ceramides in living cells reveals

Jan 13, 2020 · First, traceless Staudinger ligation enabled enamide formation between sterically encumbered alkenyl azides and newly designed phosphinophenol esters. Second, application of Eu(OTf) 3 led to chemoselective removal of the enamide Boc groups without detaching the resin linker. Abstract Chemical ligations to form native peptides from N→N acyl migrations in Trp‐containing peptides via 10‐ to 18‐membered cyclic transition states are described. Jul 17, 2018 · The salicylaldehyde group is released spontaneously during the reaction, resulting in the traceless formation of ceramide, without the introduction of any extraneous chemical moieties (Fig. 1A). From these initial experiments, we found that compound 3 offered superior hydrolytic stability, showing very little degradation (<2%) over 16 h (Fig. 1B O-acyl peptides in traceless chemical ligation reactions is sup-ported by theoretical and computational studies. Further ligation. investigations on other sized transition sta tes as well as Herein, we report a traceless ligation at Val-Xaa sites under mild thiol additive-free reaction conditions, whereby the introduction of β-mercaptan on the C-terminal valine residue effectively activates the otherwise unreactive N-acyl-benzimidazolinone (Nbz), and enables the use of a one-pot ligation–desulfurization strategy to generate the