PEGylation
The covalent attachment of polyethylene glycol (PEG) chains to a peptide. PEGylation increases molecular size, reduces renal clearance, and extends half-life. Used in semaglutide and other long-acting peptide drugs.
Frequently Asked Questions
What is PEGylation?
Why is PEGylation important in peptide research?
Related Terms
The time required for the concentration of a peptide in the body to decrease by half. Determines dosing frequency — short half-life peptides (minutes) need daily dosing, while long half-life peptides (days) can be dosed weekly.
Renal clearanceThe removal of a peptide from the blood by the kidneys. Smaller peptides (below ~60 kDa) are filtered by the glomerulus. PEGylation increases molecular size to reduce renal clearance and extend half-life.
Molecular weightThe sum of atomic weights of all atoms in a peptide molecule, measured in Daltons (Da). Peptides are generally 500–5,000 Da; larger molecules are classified as proteins. Molecular weight affects bioavailability and delivery route.