Efficient N-terminal labeling of proteins by use of sortase
"Sorting out" N-terminal labeling: The reversibility of transpeptidase reactions makes protein N-terminal labeling challenging. Depsipeptide substrates for sortase A release alcohol by-products, which are poor nucleophiles for the reverse reaction, during ligation. Proteins with an unhindered N-terminal glycine residue can be labeled efficiently with only a minimal excess of the labeling reagent (see scheme).
Williamson, Daniel J.,Fascione, Martin A.,Webb, Michael E.,Turnbull, W. Bruce
supporting information
p. 9377 - 9380
(2012/11/06)
Synthesis of the Rheb and K-Ras4B GTPases
Now available! Farnesylated and carboxymethylated Rheb (see picture) and K-Ras4B GTPases were synthesized in useful amounts by a combination of expressed protein ligation and solid-phase lipopeptide synthesis. The functionality of the proteins was proven by biochemical, biophysical, and cell-based investigations.