الفهرس | Only 14 pages are availabe for public view |
Abstract Molecular cloning provides a powerful way to investigate the structure and function of surface proteins and to express them for large scale protein production. Complementary DNA (cDNA) cloning strategies can be used to analyse new membrane proteins. So far, the cloning of new membrane proteins still depends on the rate at which monoclonal antibodies are raised and analysed. Large number of monoclonal antibodies have not been raised against the surface proteins of many tissues. Epitope insertion mutagenesis (EIM) has been devised to clone cDNAs encoding membrane proteins in a way that should avoid the existing need to develop antibodies against individual membrane proteins. This is of particular importance when the suitable tissue is not available in sufficient quantities to allow a sturation analysis of surface proteins through the raising of monoclonal antibodies as in case of early embryonic and extra embryonic tissues. In contrast, cDNA libraries can readily be made from small quantities of starting tissues, can be propagated in bacteriological cells and expressed at a relatively high level in mammalian cells through a range of specialised expression vectors. Thus, a method for screening cDNA libraries for sequences encoding membrane proteins should greatly accelerate the rate of discovery of membrane proteins and by directly yielding cDNA clones, would provide immediate access to the structure of encoded polypeptide. |