A versatile method of ribosomal synthesis of peptides containing long chain fatty acids at the N-terminus

Abstract The N-terminal modification of peptides and proteins with long chain fatty acids (LCFAs) plays an important role in their cellular bioactivity and localization. Such modifications are generally carried out by specific enzymes in a post-translation manner, and therefore an alteration of the N-terminal modifying groups requires either engineering the enzymes or their unusual intrinsic promiscuity. Here we report a versatile method using an approach of in vitro ribosomal synthesis of peptides containing various long fatty acids at the N-terminus. We charged Gly on an initiator tRNA by flexizyme, and then the free N-amino group was chemically acylated with myristoyl chloride and applied to the ribosomal synthesis of a myristoyl-peptide according to the designated mRNA template sequence. This approach turns out to be applicable for a wide array of not only initiator amino acids but also LCFAs. To this end, we have demonstrated the ribosomal synthesis of the Myrcludex B, an inhibitor peptide of hepatitis B virus infection containing the myristoyl group, and its variants containing other LCFA groups.