Disulfide bonds are an integral part of the three-dimensional structure of many proteins. We find these covalent bonds in almost all extracellular peptides and protein molecules.
Before solid phase synthesis of polypeptide, it is necessary to design the formation sequence and method route of multiple disulfide bonds in advance, select different side chain sulfhydryl protection groups, and use their different protection groups to form two or more pairs of disulfide bonds by step oxidation. Trt,Acm,Mmt,tBu,Bzl and other groups are often used as sulfhydryl protection groups.
The formation of disulfide bond has always been a difficult point in peptide synthesis. After unremitting research and accumulation, the bright organisms have developed the mature multi-disulfide ring formation technology and can synthesize three and four disulfide polypeptides with high success rate.