Synthesis and folding of a mirror-image enzyme reveals ambidextrous chaperone activity

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 111; no. 32; pp. 11679 - 11684
• Main Authors: Weinstock, Matthew T., Jacobsen, Michael T., Kay, Michael S.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 12.08.2014; National Acad Sciences
• Subjects: Amino Acid Sequence; Amino Acids - chemistry; Biochemistry; Biological Sciences; Biophysical Phenomena; Biosynthesis; Chaperonin 10 - metabolism; Chaperonin 60 - metabolism; Chemical synthesis; Chemicals; Enzyme activity; Enzymes; Enzymes - biosynthesis; Enzymes - chemistry; Enzymes - genetics; Escherichia coli; Escherichia coli Proteins - biosynthesis; Escherichia coli Proteins - chemistry; Escherichia coli Proteins - genetics; Hydrazides; Hydro-Lyases - biosynthesis; Hydro-Lyases - chemistry; Hydro-Lyases - genetics; Ligation; Models, Molecular; Molecular Chaperones - metabolism; Molecular Sequence Data; Picolinic Acids - metabolism; Protein Folding; Protein refolding; Protein Structure, Quaternary; Proteins; Stereoisomerism; Synthetic biology; protein folding; peptide synthesis
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1410900111

Mirror-image proteins (composed of d -amino acids) are promising therapeutic agents and drug discovery tools, but as synthesis of larger d -proteins becomes feasible, a major anticipated challenge is the folding of these proteins into their active conformations. In vivo, many large and/or complex proteins require chaperones like GroEL/ES to prevent misfolding and produce functional protein. The ability of chaperones to fold d -proteins is unknown. Here we examine the ability of GroEL/ES to fold a synthetic d -protein. We report the total chemical synthesis of a 312-residue GroEL/ES-dependent protein, DapA, in both l - and d -chiralities, the longest fully synthetic proteins yet reported. Impressively, GroEL/ES folds both l - and d -DapA. This work extends the limits of chemical protein synthesis, reveals ambidextrous GroEL/ES folding activity, and provides a valuable tool to fold d -proteins for drug development and mirror-image synthetic biology applications.