PDI (蛋白质二硫化物异构酶)

PDI (Protein disulfide isomerases) is a 55-kDa protein and consists of four domains namely a, b, b', a'. PDI is an abundant enzyme in the endoplasmic reticulum (ER). PDI, a prototypic thiol isomerase, is an important oxidase, reductase, isomerase and molecular chaperone. It can distinguish between partially folded, unfolded, and properly folded protein substrates, and catalyze the formation and cleavage of thiol-disulfide bonds during protein folding in the ER. PDI can also maintain active conformation of the β subunit of collagen prolyl 4-hydroxylase and stabilization of the major histocompatibility complex's (MHC) class 1 peptide loading complex (PLC). PDI expression is up-regulated in select types of cancers^[1][2].