Membranes of Normal Hamster Lymphocytes and Lymphoid Cells Neoplastically Transformed by Simian Virus 40. II. Plasma Membrane Proteins Analyzed by Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis and Two-Dimensional Immune Electrophoresis2

Abstract

The plasma membrane proteins of lymphocyte populations from normal outbred Syrian hamsters were compared with those of a neoplastic transformant line (GD 248) induced by simian virus 40. Both quantitative and qualitative differences were observed. Gradient dodecyl sulfate-polyacrylamide gel electrophoresis revealed 12 major protein components in the membranes of both cell populations. Both membrane categories also contained small amounts of immunoglobulin. Compared with the membranes of the reference cell population, GD 248 membranes showed a 60% decrease of approximately 210,000 daltons of glycoprotein; a 10% reduction of about a 48,000-dalton band and virtually complete loss of a 15,000-dalton component concomitant with a 57% increase in a 52,000-dalton band; fusion to two subcomponents (mol wt approximately 250,000 daltons); and emergence of approximately 120,000 and 30,000 daltons glycoproteins. In addition, the relative mobility of an approximately 95,000-dalton component increased by roughly 0.02 U. Crossed immune electrophoresis in Trition X-100 with heterologous antiserum against GD 248 microsomal membranes revealed both a new component with a high level of electrophoretic mobility and intensification and additional heterogeneity in a strongly antigenic component with a low level of electrophoretic mobility. Crossed-line immune electrophoresis indicated that at least two antigens in the membranes of GD 248 cells lacked the membranes of the reference cell population.