Structure and modification
Structure and modification: 6 articles from Peptides Facts. Evidence-led reference on research peptides.
Antibody-Peptide Conjugates: A Half-Life by Design
Lipidation tethers a peptide to albumin and PEGylation adds bulk. The third strategy borrows the longest-lived protein in plasma and makes it pharmacologically active in its own right.
Cyclisation: Locking a Peptide Into One Shape
A linear peptide in solution is a population of thousands of conformations, only one of which binds. Closing the chain into a ring removes most of the rest before the receptor is ever encountered.
D-Amino Acid Substitution and Protease Resistance
Proteases are stereospecific enzymes. Invert one stereocentre at the bond they cut and the cut stops happening. The cost is that the receptor is stereospecific too, and it does not always forgive the same change.
Disulfide Bonds and Why Some Peptides Have a Shape at All
Most short peptides have no fixed structure. The ones that do usually owe it to a covalent bridge between two cysteines, and that bridge is both the reason they work and the first thing to fail.
Lipidation and Albumin Binding: How a Fatty Acid Buys a Week of Half-Life
A single fatty acid chain, hung off one lysine through a short spacer, turns a peptide that survives two minutes into one that survives a week. It works not by protecting the peptide but by tethering it to albumin.
PEGylation: What a Polymer Chain Buys and What It Costs
Attaching polyethylene glycol was the dominant half-life extension strategy for three decades. It works, the mechanism is well understood, and the field has quietly moved away from it. Both halves of that sentence deserve explaining.