Specificity
This antibody recognises brain glycogen phosphorylase, a regulatory enzyme which catalyses the rate-determining step in glycogen degradation. Mammalian glycogen phosphorylase is found as three major isozymes including muscle (GPMM), liver (GPLL), and brain (GPBB), which can be distinguished by their structural and functional properties as well as by the tissues in which they are expressed. GPBB is thought to function in the release of emergency glucose during stress, and in embryogenesis where it is the predominant isozyme. GPBB is also expressed in the early stages of gastric and colorectal cancers.