Research peptide glossary
Definitions for the most-used terms in peptide research, laboratory practice, and UK regulation. Each term has its own page with deeper context and links to related peptides.
For laboratory and research use only — not for human consumption.
Angiogenesis
The formation of new blood vessels from pre-existing vasculature.
ATP synthase
Mitochondrial F0F1 enzyme that synthesises ATP by harnessing the proton gradient across the inner mitochondrial membrane.
Autophagy
Cellular self-digestion pathway that clears damaged organelles and protein aggregates; principal cellular quality-control mechanism.
Bacteriostatic water
Sterile water containing 0.9% benzyl alcohol as a bacteriostatic preservative — the standard peptide reconstitution vehicle.
BDNF
Brain-derived neurotrophic factor — the principal neurotrophin supporting neuronal survival, synaptic plasticity, and neurogenesis.
Bioavailability
Fraction of an administered dose that reaches systemic circulation in unchanged form.
Cationic amphipathic helix
α-helical structural motif of antimicrobial peptides with one cationic face and one hydrophobic face — drives selective membrane disruption.
Certificate of Analysis (CoA)
Batch-specific document reporting purity, identity, and contaminant results for a research peptide lot.
Claudin
Family of tetraspan transmembrane proteins forming the sealing strand of epithelial tight junctions; determines paracellular permeability selectivity.
Collagen
The most abundant structural protein in the body, organised into types with distinct tissue roles.
Endotoxin
Bacterial lipopolysaccharide that triggers TLR4-mediated inflammation; a critical research-peptide quality control parameter.
Enthesis
The fibrocartilaginous insertion of tendon or ligament into bone — the anatomical zone where most repair failures occur.
Fibroblast
Connective-tissue cell that synthesises collagen and the extracellular matrix.
GHRH
Hypothalamic peptide that stimulates anterior-pituitary growth-hormone release.
GHRP
Synthetic peptide that stimulates GH release by acting at the ghrelin (GHSR) receptor.
GHSR
The ghrelin receptor — G-protein-coupled receptor through which GHRPs and ibutamoren stimulate GH release.
GIP
Glucose-dependent insulinotropic peptide — an intestinal incretin hormone released after carbohydrate or fat ingestion.
GLP-1
Glucagon-like peptide-1 — incretin hormone secreted by intestinal L-cells that drives glucose-dependent insulin release.
GLP-1R
G-protein-coupled receptor for GLP-1; molecular target of incretin-class metabolic peptides.
Half-life
Time for the plasma concentration of a substance to fall to half its initial value.
HPLC
High-performance liquid chromatography — the principal method for assessing peptide purity.
Hydroxyproline
Post-translationally hydroxylated proline residue characteristic of collagen; principal biochemical readout for tissue collagen content.
IGF-1
Insulin-like growth factor 1 — the principal downstream mediator of growth-hormone effects on tissue growth.
IGF-1R
Transmembrane tyrosine-kinase receptor for IGF-1, structurally related to the insulin receptor.
IL-6
Pleiotropic cytokine bridging pro-inflammatory NF-κB signalling and the acute-phase response; principal downstream endpoint in inflammation research.
Incretin effect
The greater insulin secretion observed after oral glucose ingestion compared with isoglycaemic intravenous glucose — mediated by GLP-1 and GIP.
IU vs mg
Two distinct unit systems used in peptide and biologic dosing — IU is a potency-based unit, mg a mass-based unit.
LAL test
Limulus amebocyte lysate assay — the standard method for quantifying bacterial endotoxin contamination.
Lipolysis
The enzymatic breakdown of triglycerides into glycerol and free fatty acids, predominantly in adipose tissue.
Lyophilisation
Freeze-drying process used to stabilise peptides as a dry powder.
MC4R
Hypothalamic G-protein-coupled receptor for α-MSH; regulates appetite, energy balance, and sexual function.
MHRA
UK Medicines and Healthcare products Regulatory Agency — licenses medicines for UK use.
MMP (Matrix metalloproteinase)
Matrix metalloproteinase — zinc-dependent enzyme that remodels the extracellular matrix.
mTOR
Serine/threonine kinase that integrates growth, nutrient, and stress signals to regulate cell growth and protein synthesis.
Myofibroblast
A contractile fibroblast phenotype expressing α-smooth-muscle actin; central driver of wound contraction and fibrotic scarring.
NAD+
Nicotinamide adenine dinucleotide — an essential metabolic coenzyme whose decline with age is a target of longevity research.
NF-κB
Nuclear factor kappa B — a transcription factor central to inflammatory gene expression.
NGF
Nerve growth factor — the prototype neurotrophin; supports sympathetic and sensory neuron survival and regeneration.
PepT1
Intestinal di-/tripeptide transporter that drives oral absorption of small peptides and peptidomimetics.
Peptide bond
The amide linkage between the α-carboxyl of one amino acid and the α-amino group of the next; the structural backbone of all peptides.
Reconstitution
Dissolving a lyophilised peptide in an appropriate aqueous vehicle prior to research use.
ROS
Reactive oxygen species — superoxide, hydrogen peroxide, hydroxyl radical, and singlet oxygen; modulated by anti-oxidant peptides.
SC vs IM
Two parenteral injection routes for peptides — SC into adipose tissue, IM into skeletal muscle — with distinct PK profiles.
Secretagogue
A substance that stimulates the secretion of an endogenous compound — most commonly applied to GH-releasing peptides.
Sirtuin
Family of NAD+-dependent protein deacetylases that regulate metabolism, stress response, DNA repair, and longevity.
Telomere
Repetitive (TTAGGG)n DNA-protein structure that caps and protects chromosome ends; shortens with each cell division.
Tenocyte
Specialised fibroblast forming the cellular component of tendons.
Tight junction
Cell-cell adhesion complex regulating paracellular transport in epithelia.
TNF-α
Pro-inflammatory cytokine central to the NF-κB signalling cascade; principal downstream readout in anti-inflammatory peptide research.
VEGF
Vascular endothelial growth factor — signals new blood-vessel formation.
WADA Prohibited List
Annual list published by the World Anti-Doping Agency classifying substances and methods banned in sport.
Zonulin
Endogenous protein that regulates intestinal tight-junction permeability and the molecular target of larazotide.
α-MSH
α-melanocyte-stimulating hormone — POMC-derived tridecapeptide acting at melanocortin receptors; parent molecule of KPV.
β-oxidation
Mitochondrial pathway that catabolises fatty acids into acetyl-CoA for ATP generation through the citric-acid cycle.