Native Chemical Ligation
Native Chemical Ligation — A chemoselective reaction between a C-terminal thioester and an N-terminal cysteine to form a native peptide bond, enabling synthesis of large peptides.
What Is Native Chemical Ligation?
Native chemical ligation (NCL) is a chemoselective reaction that joins two unprotected peptide fragments through a native peptide bond at a cysteine junction. Developed by Philip Dawson and Stephen Kent in 1994, NCL revolutionized chemical protein synthesis by enabling the assembly of proteins too large for single-run SPPS.
Reaction Mechanism
- C-terminal thioester fragment reacts with N-terminal cysteine of the second fragment
- Transthioesterification forms a thioester-linked intermediate
- Spontaneous S-to-N acyl shift generates the native amide bond
Applications
Synthesis of proteins > 50 amino acids, site-specific incorporation of non-natural amino acids at any position, isotopic labeling of specific protein segments for NMR, and synthesis of mirror-image (D-protein) drug candidates. NCL has enabled total chemical synthesis of proteins up to 300+ residues.
Frequently Asked Questions
What is Native Chemical Ligation?
A chemoselective reaction between a C-terminal thioester and an N-terminal cysteine to form a native peptide bond, enabling synthesis of large peptides.
Why is Native Chemical Ligation important in peptide research?
Native Chemical Ligation is a fundamental concept in synthesis as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.
Authority Sources
- Native Chemical Ligation on Wikipedia
- Search Native Chemical Ligation on PubChem (NIH)
- Research articles on ScienceDirect