9] Use of proteases for the study of membrane insertion

Abstract

Publisher Summary Proteases are used to study the mechanism by which newly synthesized membrane proteins recognize their destined subcellular organelles and to examine whether the newly synthesized polypeptides are inserted into the subcellular membranes properly. This chapter provides an overview of the process of membrane protein insertion, and focuses on the aim and step(s) in which proteases are used. The study of mechanisms by which newly synthesized proteins are properly inserted into membranes, followed by intracellular transport to their final destination or site of function, is essential to the understanding of membrane biogenesis. The use of proteases is an important technique in an analysis of early events in membrane biogenesis, but this technique can be successfully applied only to certain types of membrane proteins. Although, proteases are successfully used in combination with enzymic and affinity-labeling techniques in the analysis of membrane protein orientation, these methods are not for the study of the insertion of the newly synthesized proteins in vitro , such as Ca 2+ -ATPase, and cytochrome b 5 .