The development of a method is described for the chemical labeling of proteins which occurs with high target specificity, proceeds within seconds to minutes, and offers a free choice of the reporter group. The method relies upon the use of peptide templates, which align a thioester and an N-terminal cysteinyl residue such that an acyl transfer reaction is facilitated at nanomolar concentrations. The protein of interest is N-terminally tagged with a 22 aa long Cys-E3 peptide (acceptor), which is capable of forming a coiled-coil with a reporter-armed K3 peptide (donor). This triggers the transfer of the reporter to the acceptor on the target protein. Because ligation of the two interacting peptides is avoided, the mass increase at the protein of interest is minimal. The method is exemplified by the rapid fluorescent labeling and fluorescence microscopic imaging of the human Y2 receptor on living cells.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/anie.201403214 | DOI Listing |
Org Biomol Chem
January 2025
School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, 3010, Victoria, Australia.
Despite advances in solid phase peptide synthesis and peptide ligation, challenges remain in the assembly of polypeptides through coupling of peptide fragments. Herein we describe a new method for peptide fragment coupling employing the Ag(I)-promoted transformation of peptide thioamides. This process proceeds an isoimide-tethered intermediate, which undergoes an O-N acyl transfer to generate the polypeptide.
View Article and Find Full Text PDFCell Death Discov
January 2025
Department of Gynaecology and Obstetrics, Xijing Hospital, Air Force Medical University, Xi'an, China.
Mitochondrial dysfunctions are closely associated with different types of disease, including cancer. Carnitine acetyltransferase (CRAT) is a mitochondrial-localized enzyme catalyzing the reversible transfer of acyl groups from an acyl-CoA thioester to carnitine and regulates the ratio of acyl-CoA/CoA. Our bioinformatics analysis using public database revealed a significant decrease of CRAT expression in ovarian cancer (OC).
View Article and Find Full Text PDFJ Org Chem
January 2025
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, People's Republic of China.
We herein disclose a visible-light-induced synthesis of aryl esters through the cross-dehydrogenative coupling of aldehydes with phenols using BrCCl, in which phenolate functions as both a substrate and a photosensitizer. This transition-metal- and photocatalyst-free visible-light-induced esterification is suitable for a wide range of substrates and gives moderate to excellent yields (up to 95%). Mechanistic studies provided evidence of a self-propagating radical reaction involving homolytic cleavage of the aldehydic C-H bond and the formation of acyl bromides.
View Article and Find Full Text PDFAnal Chem
January 2025
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
Lipid A, a well-known saccharolipid, acts as the inner lipid-glycan anchor of lipopolysaccharides in Gram-negative bacterial cell membranes and functions as an endotoxin. Its structure is composed of two glucosamines with β(1 → 6) linkages and various fatty acyl and phosphate groups. The lipid A structure can be used for the identification of bacterial species, but its complexity poses significant structural characterization challenges.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Institute of Environmental Engineering, School of Metallurgy and Environment, Central South University, Changsha 410083, China; Chinese National Engineering Research Center for Control & Treatment of Heavy Metal Pollution, Changsha 410083, China. Electronic address:
Quorum sensing (QS) is recognized for enhancing bacterial resistance against heavy metals by regulating the production of extracellular substances that hinder metal penetration into the intracellular environment. However, it remains unclear whether QS contributes to resistance by regulating electron transfer, thereby transforming metals from more toxic to less toxic forms. This study investigated the regulatory mechanism of acyl-homoserine lactone (AHL)-mediated QS on electron transfer under As(III) and Cr(VI) stress.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!