Peptide Chemistry Glossary
Definitions of the chemistry, analytical and pharmacology terms used across Peptide Properties.
- Aib (α-aminoisobutyric acid)
- A non-proteinogenic amino acid that is often placed in synthetic peptides to resist cleavage by the enzyme DPP-4.
- Amidation (C-terminal amide)
- Replacement of a peptide’s C-terminal carboxylic acid with an amide group. It changes the molecular formula by –O +NH.
- CAS number
- A unique numeric identifier that the Chemical Abstracts Service assigns to a chemical substance.
- Certificate of analysis (COA)
- A batch-specific document that reports analytical results such as HPLC purity and mass-spectrometry identity.
- GHRH
- Growth hormone–releasing hormone, a 44-residue hypothalamic peptide. Sermorelin and tesamorelin are analogs of it.
- GHS-R1a
- The growth hormone secretagogue receptor (ghrelin receptor), targeted by ipamorelin, GHRP-2, GHRP-6 and hexarelin.
- GLP-1 receptor
- The receptor for glucagon-like peptide-1, a class B G-protein-coupled receptor targeted by incretin-based peptides.
- HPLC
- High-performance liquid chromatography, used to separate a sample’s components and estimate peptide purity.
- InChIKey
- A fixed-length hashed form of the IUPAC International Chemical Identifier, used to look up a structure across databases.
- Lyophilization
- Freeze-drying: water is removed from a frozen sample by sublimation, leaving a dry solid.
- Mass spectrometry (MS)
- An analytical method that measures mass-to-charge ratios and is used to confirm a peptide’s identity from its molecular mass.
- Molecular weight
- The sum of the average atomic masses in a molecule, in g/mol (daltons).
- Monoisotopic mass
- The mass of a molecule calculated from the most abundant isotope of each element. It is used in high-resolution mass spectrometry.
- PubChem CID
- The Compound Identifier in PubChem, the open chemistry database run by the U.S. National Library of Medicine.
- Short peptide bioregulator
- A di-, tri- or tetrapeptide from the Khavinson research program, studied for tissue-specific gene-regulatory activity.
- TFA salt
- A trifluoroacetate counter-ion form common in synthetic peptides. It raises the apparent mass compared with the free peptide.
- UNII
- The FDA Unique Ingredient Identifier, a code assigned to substances in the FDA Global Substance Registration System.