disulphide bond in a protein is generated between
Disulfide Disulfide bonds in proteins are formed between the thiol groups of cysteine residues by the process of oxidative folding. The other sulfur-containing amino acid, methionine, cannot form disulfide bonds. A disulfide bond is typically denoted by hyphenating the abbreviations for cysteine, e.g., when referring to ribonuclease A the "Cys26–Cys84 disulfide bond", or the "26–84 disulfide bond", or most simply as "C26–C84"[10] where the disulfide bond is understood and does not need to be mentioned. The prototype of a protein disulfide bond is the two-amino-acid peptide cystine, which is composed of two cysteine amino acids joined by a disulfide bond (shown in Figure 3 in its unionized form). The structure of a disulfide bond can be described by its χss dihedral angle between the Cβ−Sγ−Sγ−Cβ atoms, which is usually close to ±90°.
Mitochondrial intermembrane space The intermembrane space is chemically similar to cytosol, but includes a large amount of small proteins as well. As electrons move down the proteins in the electron transport chain, the electrons lose energy to bring H+ ions from the mitochondrial matrix into the intermembrane space. As a concentration gradient of hydrogen ions forms, a protein called ATP synthase harnesses the potential energy of these ions and starts chemiosmosis, where the H+ ions reenter the matrix via this enzyme bound to the cristae (folds of the inner membrane). ADP and a phosphate group are combined to form ATP.