We propose to isolate and characterize in detail a group of receptor-bearing protein & glycoprotein components from purified plasma membranes of the guinea pig L2C lymphoblastic leukemia. This system is unique in its ability to provide very large numbers (greater than 10" per week) of viable, homogeneous single cells, grown in vivo, which have a group of important plasma membrane components: a tumor specific transplantation antigen, guinea pig strain 2 histocompatibility antigen, complement (C3) receptor, immunoglobulin (IgG2), blood group i antigen, two lectin receptors (Phaseolus vulgaris and Ricin communis) and an insulin receptor. These same components have been found on some human normal and acute or chronic lymphoblastic leukemia cells. We will use an automated, highly sensitive assay system for monitoring plasma membrane purification and subsequent component purification. N2 cavitation will be used for L2C disruption, and plasma membrane vesicles will be purified by differential centrifugation, zonal centrifugation and specific affinity binding. The plasma membranes will be solubilized and the components will be purified by a combination of classical protein isolation methods, hydrophobic chromatography and specific affinity chromatography. Analysis of components will include: cell cycle variation, biosynthesis and chemical and physical characterization. Where feasible, correlative studies will be performed with normal guinea pig lymphocytes. This study will provide basic information of the structure and synthesis of components of the plasma membrane and this will facilitate the understanding of their function.
NIH ExPorter
NIH ExPorter