Glossary
Recombinant
Recombinant means produced by an engineered host cell rather than by chemistry. Where the crossover with synthesis sits and what impurities differ.
Recombinant production means the target peptide or protein is expressed by a living host cell engineered to carry its gene, rather than assembled chemically. Typical hosts are E. coli, Pichia or Saccharomyces yeast, and mammalian CHO lines; the product is then extracted, refolded if necessary, and purified by chromatography.
Why recombinant matters in peptide research
Length decides the route. Chemical solid-phase synthesis is efficient to roughly 50 residues, beyond which cumulative coupling losses make yields impractical; recombinant expression handles long chains and whole proteins comfortably and can install disulfide bonds and, in eukaryotic hosts, glycosylation. Insulin, growth hormone and full-length thymosin beta-4 are recombinant products, while short signalling peptides and fragments are synthetic.
The impurity profiles differ, and that drives what a certificate of analysis should report. Synthetic material carries deletion sequences and residual solvents; recombinant material carries host cell protein, host DNA and — for bacterial hosts — endotoxin, which must be tested separately because HPLC purity will not reveal it. Recombinant material is also more prone to lot-to-lot variability. See how to read a COA.
Related terms
native sequence · analog