Tsüstiinijäägi

Tsüstiinijäägi, sometimes referred to as cystine residue or cystinyl moiety, is a chemical term describing a part of a protein or peptide molecule that originates from the amino acid cysteine. When two cysteine molecules react, they form a disulfide bond (-S-S-), a covalent linkage that can significantly impact the three-dimensional structure and stability of a protein. The term "tsüstiinijäägi" specifically refers to the remaining portion of a cysteine molecule after it has formed this disulfide bond.

Disulfide bonds are crucial for the function of many proteins, particularly those that need to maintain a specific shape for their activity. They can be found within a single polypeptide chain, stabilizing its structure, or between two separate polypeptide chains, holding them together. The presence and location of tsüstiinijäägi are therefore important considerations in understanding protein folding, stability, and biological activity. In some contexts, the term might also be used to describe a cysteine residue that has undergone other modifications, though the disulfide bond formation is the most common association.