Glossary

A structural modification that adds an acetyl group to a peptide, most often at the N-terminus. It is recorded as part of a peptide's chemical description.

See also: N-terminus · Modification

A molecule that binds to a receptor and is referenced in research as producing a response at that receptor. Used descriptively in literature to characterize how a material interacts with a target.

See also: Receptor · Analog

A structural modification in which a peptide's C-terminus is converted to an amide group. C-terminal amidation is a common feature noted in a peptide's description.

See also: C-terminus · Modification

A small organic molecule that serves as a building block of peptides and proteins. Amino acids link together through peptide bonds to form a chain.

See also: Peptide · Peptide sequence

A molecule with a structure closely related to a reference compound, differing by one or more modifications to the sequence or chemistry. Analogs are studied to compare structural variants.

See also: GHRH analog · Peptide sequence

A class of peptides commonly referenced in research involving host-defense and antimicrobial activity. The term describes a research area, not an application of any catalog material.

See also: Peptide · Receptor

A descriptive field on documentation reporting the physical form of a material. For a lyophilized peptide, appearance is typically recorded as a white to off-white powder or cake.

See also: Lyophilized / Lyophilization · Certificate of Analysis (COA)

An analytical test or the numeric result it produces, such as an HPLC purity assay. Assay values are recorded on a Certificate of Analysis for a specific batch.

See also: HPLC · Purity · Certificate of Analysis (COA)

The set of records that describe and identify a specific batch of material, anchored to its lot or batch number. Batch documentation supports traceability between a material and its analysis.

See also: Lot / Batch number · Certificate of Analysis (COA)

A defined mixture of two or more peptide materials supplied together and documented by its component identities.

See also: Peptide · Batch documentation

The end of a peptide chain that terminates in a free carboxyl group. Sequences are conventionally written from the N-terminus to the C-terminus.

See also: N-terminus · Peptide sequence

A document reporting the analytical test results for a specific batch of material, including identity, purity, and related measurements. A COA is tied to a lot number and confirms a material against its specification.

See also: Purity · HPLC · Mass spectrometry (MS) · Lot / Batch number

A family of separation techniques, including HPLC, that resolve a mixture into its components based on how they interact with a stationary phase. Chromatography underlies most purity analysis.

See also: HPLC · Purity

A peptide chemically linked to another molecule, such as a metal ion or carrier group. The conjugated form is part of the material's identity — for example, a copper peptide.

See also: Modification · Analog

A charged species, such as acetate or trifluoroacetate, associated with a peptide to balance its charge. The salt form affects net peptide content and appearance.

See also: Net peptide content · Trifluoroacetic acid (TFA)

A peptide whose chain is joined into a ring, for example through a disulfide bond or head-to-tail linkage, often studied for its distinct structure and stability.

See also: Disulfide bond · Peptide sequence

A unit of molecular mass equal to one atomic mass unit, used to express the molecular weight of peptides and proteins.

See also: Molecular weight · Mass spectrometry (MS)

A covalent bond between two cysteine residues that can stabilize a peptide's folded structure. Its presence or absence is part of a peptide's structural definition.

See also: Cyclic peptide · Secondary structure

A bacterial contaminant that may be measured and reported as part of the analytical characterization of a material where relevant. Reported as a quantitative field on documentation.

See also: Certificate of Analysis (COA) · Grade

A shorter portion of a larger peptide or protein sequence, sometimes studied on its own as a defined research material.

See also: Peptide sequence · Analog

An analog structurally related to growth-hormone-releasing hormone, referenced in research involving growth hormone axis and pituitary signaling pathways.

See also: Analog · Receptor

A designation indicating the intended context and specification level of a material. In this catalog, materials are designated for research use only.

See also: Research use only (RUO) · Purity

A research measure of how long a material persists before half of it is degraded or cleared in a given system. It is used descriptively to compare stability, not as guidance for use.

See also: Stability · Protease

The degree of similarity between two peptide or protein sequences, used to compare related materials and analogs.

See also: Peptide sequence · Analog

High-performance liquid chromatography, an analytical technique that separates a sample into its components as they pass through a column. HPLC is commonly used to estimate peptide purity from the relative areas of the resulting peaks.

See also: Purity · Certificate of Analysis (COA)

Liquid chromatography coupled to mass spectrometry — a combined technique that separates components and measures their masses, used for identity and purity characterization.

See also: HPLC · Mass spectrometry (MS)

A molecule that binds to a specific target such as a receptor. Peptides are studied as ligands in research describing molecular interactions.

See also: Receptor · Agonist

A unique identifier assigned to a defined quantity of material produced together. The lot number ties the material to its Certificate of Analysis and batch records, enabling traceability.

See also: Batch documentation · Certificate of Analysis (COA)

Lyophilization, or freeze-drying, removes water from a material by sublimation under low temperature and reduced pressure, producing a dry, porous solid. Peptide research materials are commonly supplied in lyophilized form.

See also: Appearance · Solubility

An analytical technique that measures the mass-to-charge ratio of ionized molecules, allowing a peptide's molecular weight to be determined and compared with the value expected from its sequence.

See also: Molecular weight · Certificate of Analysis (COA)

A chemical change to a peptide's residues or termini — such as amidation, acetylation, or conjugation — that distinguishes it from the unmodified sequence.

See also: Amidation · Acetylation

A notation stating the count of each element in a molecule. Together with the sequence and molecular weight, it is one of the defining chemical descriptors of a peptide.

See also: Molecular weight · Peptide sequence

The mass of one molecule of a compound, commonly expressed in daltons or grams per mole. Molecular weight is compared against the value measured by mass spectrometry to confirm identity.

See also: Mass spectrometry (MS) · Molecular formula

The end of a peptide chain that terminates in a free amino group; the conventional starting point when writing a sequence.

See also: C-terminus · Peptide sequence

The proportion of a material's total mass that is peptide, distinct from chromatographic purity. Non-peptide components such as residual water and counter-ions reduce net peptide content.

See also: Purity · Appearance

A short chain of amino acids joined by peptide bonds. Peptides are generally shorter than proteins and are identified by their amino acid sequence.

See also: Amino acid · Peptide sequence

The covalent amide bond linking the carboxyl group of one amino acid to the amino group of the next, forming the backbone of a peptide chain.

See also: Amino acid · Peptide

The specific order of amino acids in a peptide chain, written from the amino end (N-terminus) to the carboxyl end (C-terminus). The sequence is the primary way a peptide is identified.

See also: Amino acid · Peptide

A longer chain of amino acids linked by peptide bonds. The line between a long peptide, a polypeptide, and a protein is a matter of length and convention.

See also: Peptide · Protein

The linear amino acid sequence of a peptide or protein — the most basic level of structural description.

See also: Peptide sequence · Secondary structure

An enzyme that cleaves peptide bonds. Susceptibility to proteases is a research property studied when characterizing peptides.

See also: Peptide bond · Stability

A large biomolecule made of one or more polypeptide chains folded into a defined structure. Proteins are generally larger than peptides.

See also: Polypeptide · Peptide

A measure, most often reported by HPLC as a percentage, of the proportion of a sample attributed to the target peptide. Purity describes the chromatographic profile and is distinct from net peptide content.

See also: HPLC · Net peptide content · Certificate of Analysis (COA)

An account that has passed PeptaPharma's review process confirming intended research use. Catalog detail and documentation are released to qualified accounts through a controlled access process.

See also: Research use only (RUO)

A molecular target that a peptide may bind to, referenced in research to describe interactions and signaling pathways. Used descriptively in literature, not as a claim about any material.

See also: Agonist · Antimicrobial peptide

Produced using engineered biological systems that express a peptide or protein, as opposed to chemical synthesis.

See also: Synthetic peptide · Protein

A designation identifying a material as intended for laboratory research and reference, and not for human or animal use. RUO framing keeps the catalog focused on documentation and chemistry.

See also: Qualified account · Grade

Trace solvents remaining from synthesis or purification, measured and reported on documentation where relevant.

See also: Certificate of Analysis (COA) · Grade

An individual amino acid unit within a peptide chain, so named because it is what remains after water is lost during peptide bond formation.

See also: Amino acid · Peptide sequence

Local folding patterns of a peptide backbone, such as helices and sheets, stabilized by hydrogen bonding.

See also: Primary structure · Peptide

A common method of chemically assembling a peptide one amino acid at a time on a solid support, widely used to produce synthetic peptide research materials.

See also: Synthetic peptide · Peptide sequence

A physical property describing the extent to which a material dissolves in a given solvent. Solubility may be noted on a record for reference where available.

See also: Lyophilized / Lyophilization · Appearance

The set of predefined criteria a batch must meet, such as minimum purity or appearance. A Certificate of Analysis reports results against the specification.

See also: Certificate of Analysis (COA) · Purity

A description of how well a material retains its identity and quality over time and under given storage conditions. Stability information supports proper handling of research materials.

See also: Storage · Lyophilized / Lyophilization

The conditions under which a material is kept to preserve its quality, such as temperature and protection from light and moisture. Storage guidance describes material handling only.

See also: Stability · Lyophilized / Lyophilization

A research concept relating a molecule's structure to observed activity in a model system, used to compare analogs and sequence variants.

See also: Analog · Ligand

A peptide produced by chemical synthesis rather than isolated from a biological source. Most catalog peptide materials are synthetic.

See also: Solid-phase peptide synthesis (SPPS) · Recombinant

A reagent used in peptide synthesis and purification that can remain as a counter-ion. Residual TFA is sometimes reported on documentation.

See also: Counter-ion / Salt form · Net peptide content

The amount of residual water in a material, commonly measured by Karl Fischer titration and reported on documentation for lyophilized materials.

See also: Lyophilized / Lyophilization · Net peptide content