Peptide Research Glossary: Essential Terms

A comprehensive reference of terms commonly used in peptide research. Amino Acid The building blocks of peptides and proteins. There are 20 standard amino acids used in biological systems. Acetylation The addition of an acetyl group (-COCH3) to the N-terminus of a peptide, often used to increase stability. Amidation The conversion of the C-terminal carboxyl group to an amide, which can increase peptide activity and stability. Bacteriostatic Water Sterile water containing a small amount of benzyl alcohol as a preservative, commonly used for reconstituting peptides. COA (Certificate of Authenticity) Documentation verifying the identity, purity, and quality of a peptide batch. Cyclization The process of forming a ring structure within a peptide, often increasing stability and bioactivity. Dalton (Da) The unit of molecular mass used to express peptide weight. One Dalton equals one atomic mass unit. Endotoxin A component of gram-negative bacterial cell walls that can contaminate peptide preparations. EU/mg (Endotoxin Units per milligram) The measurement unit for endotoxin contamination levels. HPLC (High-Performance Liquid Chromatography) The primary analytical technique used to determine peptide purity. Lyophilization Freeze-drying process that removes water from peptides to create stable, powder form products. LAL Test (Limulus Amebocyte Lysate) The standard test for detecting bacterial endotoxins in peptide preparations. Mass Spectrometry (MS) Analytical technique that measures the mass-to-charge ratio of ions to confirm peptide identity. Molecular Weight (MW) The sum of atomic weights of all atoms in a molecule, expressed in Daltons. Peptide Content The percentage of actual peptide in a sample, accounting for salt and water content. Purity The percentage of target peptide in a sample, as determined by HPLC analysis. Reconstitution The process of dissolving lyophilized peptide powder in a suitable solvent. Sequence The specific order of amino acids in a peptide chain. Sterility The absence of viable microorganisms in a peptide preparation. TFA (Trifluoroacetic Acid) A common counter-ion used in peptide synthesis that may be present as a salt form. Truncation The presence of peptides missing one or more amino acids from the intended sequence. Yield The amount of peptide obtained after synthesis and purification.