Cleavage
Cleavage — The breaking of a chemical bond within a molecule. In peptide chemistry, refers to removing the peptide from the resin after solid-phase synthesis.
What Is Cleavage in Peptide Synthesis?
Cleavage is the chemical step that releases the completed peptide from the synthesis resin at the end of solid-phase peptide synthesis. In Fmoc SPPS, cleavage uses 95% TFA with scavenger cocktails for 2-4 hours. This step simultaneously removes all acid-labile side-chain protecting groups.
Cleavage Cocktails
- Reagent K: TFA/thioanisole/water/phenol/EDT (82.5:5:5:5:2.5). General purpose, good for Cys-containing peptides
- Reagent B: TFA/phenol/water/TIPS (88:5:5:2). For peptides without Cys, Met, or Trp
- EDT-containing: Required for Arg(Pbf)-containing peptides to scavenge sulfonyl cations
Post-Cleavage Processing
After cleavage, the crude peptide is precipitated in cold diethyl ether, centrifuged, washed, and dried. The precipitate is dissolved in aqueous buffer for HPLC analysis and purification.
Frequently Asked Questions
What is Cleavage?
The breaking of a chemical bond within a molecule. In peptide chemistry, refers to removing the peptide from the resin after solid-phase synthesis.
Why is Cleavage important in peptide research?
Cleavage is a fundamental concept in chemistry 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.