Native Chemical Ligation
Definition
Joining two unprotected peptide fragments in solution through a cysteine at the junction, forming a normal peptide bond. It is how chains too long for stepwise synthesis are assembled.
What this means for research sourcing
Structure and identity terms are what a certificate of analysis is written in. Every Volta compound ships with its sequence, molecular weight and measured purity, so these terms map directly onto the specification on the product page.
Related Terms in Chemistry & Structure
Solution-Phase Synthesis
Building a peptide in solution, with isolation and purification between steps rather than washing a resin. It is laborious for long chains and remains economic at scale for short ones.
Active Ester
A carboxylic acid converted to an ester reactive enough to form an amide bond. It is the intermediate a coupling reagent generates, and how selective that ester is governs how much racemisation occurs.
Linker
The chemistry joining two parts that would otherwise be separate: a chain to its resin, a peptide to a carrier, or two domains of a construct. The linker decides the conditions under which the join is broken or kept.
Kaiser Test
A colour test using ninhydrin that detects free primary amines on resin beads, used to confirm a coupling went to completion. A blue result means unreacted amine remains and the coupling should be repeated.
Trityl (Trt)
A bulky acid-labile protecting group used on cysteine, histidine, asparagine and glutamine side chains. Its sensitivity to mild acid is what makes selective removal possible while other groups stay in place.
Acetamidomethyl (Acm)
A cysteine protecting group that survives the acid used for final cleavage. Leaving it on lets disulfide bridges be formed deliberately and in a chosen order rather than at random.
Dimerisation
Two molecules associating or bonding into one unit. For peptides it most often means an unintended disulfide-linked dimer, which appears as a distinct peak at twice the expected mass.
Hydrophilicity
Affinity for water. In peptides it is set by the balance of polar and charged residues, and together with its opposite it governs solubility, how the chain folds, and where it elutes in reversed-phase chromatography.