Homogeneous biosynthetic sn-glycerol-3-phosphate dehydrogenase (EC 1.1.1.8) of Escherichia coli was potently inhibited by palmitoyl-CoA and other long chain acyl-CoA thioesters. The concentration dependence of this inhibition was not cooperative. Enzyme activity was inhibited 50% at 1 PM palmitoyl-CoA; thus, this inhibition occurred at concentrations below the critical micellar concentration of...

Studying protein ubiquitination is difficult due to the complexity of the E1-E2-E3 ubiquitination cascade. Here we report the discovery that C-terminal ubiquitin thioesters can undergo direct transthiolation with the catalytic cysteine of the model HECT E3 ubiquitin ligase Rsp5 to form a catalytically active Rsp5∼ubiquitin thioester (Rsp5∼Ub). The resulting Rsp5∼Ub undergoes efficient autoubiqu...

While thiol-based catalysts are widely employed for chemical protein synthesis relying on peptide thioester chemistry, this is less true selenol-based whose development in its infancy. In study, we compared different selenols derived from the selenocysteamine scaffold their capacity to promote thiol–thioester exchanges water at mildly acidic pH and production of thioesters bis(2-sulfanylethyl)a...

Native chemical ligation (NCL) is an extremely useful method for the production of synthetic and semi-synthetic proteins. Since it is widely accepted that approximately fifty amino acid residues represents the limit for efficient automated solid phase peptide synthesis (SPPS) the use of recombinant methods for the production of the required thioester and cysteine-containing components has been ...

We report the functionalization of cysteine residues with lipophilic alkynes bearing a silyl group or an alkyl chain using amphiphilic ethynylbenziodoxolone reagents (EBXs). The reactions were carried out in buffer (pH 6 to 9), without organic co-solvent removal oxygen, either at 37 °C room temperature. transformation led significant increase peptide lipophilicity and worked for aromatic thiols...