Disulfide bridges of a cystein-rich repeat of the LDL receptor ligand-binding domain

Amino-terminal ligand-binding (LB) repeat of the human low density lipoprotein receptor is expressed as a recombinant peptide in order to analyze the disulfide-bonding pattern, and the structure and function of LB repeats. Disulfide bond connections are made in two ways. In the first way, amino acids produced from the digestion of nonspecific proteolytic enzyme proteinase K contains single disulfide bond connecting Cys(IV) and Cys(VI). In the other approach, reduction of disulfide bonds occurs.