In the active sites of serine and cysteine proteases, the eponymous residue is usually paired with a proton-withdrawing group to promote nucleophilic attack on the peptide bond.

Enzymes that catalyse the hydrolytic cleavage of peptide bonds are called proteases. Proteases fall into four main mechanistic classes: serine, cysteine, aspartyl and metalloproteases.

Certain types of peptides and microproteins for drug discovery research can be made more efficiently and quickly using a reaction solvent that helps mimic nature's way.

One of these, cysteine, was assumed not to have been present at the origin of life. ... "We have shown that nitriles possess the in-built energy required to form peptide bonds in water.

Prebiotic synthesis of cysteine peptides that catalyze peptide ligation in neutral water. Science , 2020; 370 (6518): 865 DOI: 10.1126/science.abd5680 Cite This Page : ...