Effects of glycosylation on y-Sarcoglycan
Abstract
Glycoproteins are the underappreciated stars in the world of science. These proteins – specifically, membrane-bound glycoproteins – are known to have been difficult to study, for they present many hurdles: they are complex, hydrophobic, and are stable in only highly specific environments. However, investigations into their structure and function are paramount, for glycoproteins are essential in the biological world. Glycoproteins serve as enzymes and hormones, and aid in clotting and locomotion. While there have been several studies of membrane glycoproteins, most of these have focused on their unique attribute: their association with sugar groups. It has recently been shown that it is possible to use the enzyme N-glycosyltransferase to attach sugars to proteins providing a method for in vitro glycosylation (5). Using a membrane-mimetic environment, we are attempting to utilize these methods to glycosylate a truncated form of y-Sarcoglycan (GSCGtm), a protein implicated in the disease etiology of Duchenne Muscular Dystrophy. These studies are aimed at shedding light on the effects of glycosylation on the structure and dynamics of GSCGtm, in order to provide information that can be used in future treatment modalities. For these studies, milligram amounts of pure protein are required. The work presented here highlights our successful efforts to recombinantly express and purify this membrane protein.