Lecture : Bio Notes 205 - Cysteine
Document Summary
It has a thiol (-sh) group in its side chain, which makes it a unique amino acid with several important functions. Cysteine plays a critical role in protein structure and function. Its thiol group can form disulfide bonds with other cysteine residues or other sulfur-containing molecules, allowing for the formation of stable protein structures such as the tertiary and quaternary structures of enzymes, antibodies, and other proteins. In addition to its role in protein structure, cysteine is a powerful antioxidant. Its thiol group can donate electrons to neutralize free radicals and other reactive oxygen species, protecting cells from oxidative damage. This antioxidant activity also contributes to the detoxification of harmful compounds in the liver. Cysteine is also involved in the synthesis of glutathione, a major antioxidant in the body that is involved in detoxification, immune function, and cellular signaling. Cysteine is the rate-limiting substrate for glutathione synthesis, meaning that its availability can limit the production of this important molecule.
