More peptides with backbone modifications from wild type ribosomes in vitro
By Kyle Hoffman
In the most recent issue of Organic and Biomolecular Chemistry, a paper from Matthew Hartman’s lab highlights the use of an editing-deficient valine-tRNA synthetase (ValRS T222P) to incorporate 11 non-canonical amino acids (ncAAs) into peptides synthesized in vitro .
The eleven ncAAs are comprised of L-amino acids with side chain modifications, α, α-disubstituted amino acids containing an α-methyl group, and β-amino acids. To prepare ncAA-tRNA, total tRNA was extracted from E. coli then charged by ValRS T222P. PURE in vitro translation reactions were supplemented with ncAA-tRNA for incorporation at a valine codon in an mRNA template. Interestingly, the efficiency of dual incorporation of α-methyl alanine and α-methyl serine was comparable to that of valine using an in vitro transcribed valine tRNA variant. This study demonstrates the value of ValRS T222P for production of novel ncAA-tRNAs and the synthesis of peptides with new structures and properties.
- Iqbal, Emil S., Kara K. Dods, and Matthew C. T. Hartman. 2018. “Ribosomal Incorporation of Backbone Modified Amino Acids via an Editing-Deficient Aminoacyl-tRNA Synthetase.” Organic & Biomolecular Chemistry. doi:10.1039/c7ob02931d.