Research Compounds · 4 min read
Peptides vs. Research Compounds: Why the Distinction Matters
Not every item in a research catalog is a peptide. A short guide to the chemical categories in the Steel catalog.
What makes a peptide
A peptide is a chain of amino acids linked by peptide (amide) bonds. Short chains — from two to roughly fifty residues — are generally called peptides; longer chains are typically called proteins.
Within the catalog, peptides range from a tripeptide such as KPV (Lys–Pro–Val) to much longer synthetic peptides used in receptor-signaling research.
Peptide complexes
Some materials are peptides bound to another species. GHK-Cu, for example, is the copper(II) complex of the tripeptide Gly–His–Lys. Its identity depends on both the peptide and the bound metal.
Non-peptide research compounds
NAD+ (nicotinamide adenine dinucleotide) is a coenzyme — a dinucleotide, not an amino-acid chain. 5-Amino-1MQ (5-amino-1-methylquinolinium) is a small molecule. Both are listed under Research Compounds rather than Peptides.
Why it matters for documentation
The appropriate analytical methods differ between categories. Peptide identity is typically confirmed by mass spectrometry; small molecules and coenzymes may use different reference methods. Correct categorization makes documentation easier to interpret.
