Radioiodination of surface proteins of bull spermatozoa and their characterization by sodium dodecyl sulphate-- polyacrylamide gel electrophoresis

Abstract

Surface proteins of ejaculated bull spermatozoa were radioiodinated, solubilized and characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The EM autoradiographs showed that the labeling was equally distributed to all parts of the spermatozoon and restricted to the sperm surface. The electrophoresis of solubilized radioactivity revealed 6 radioactive fractions with approximate MW of 67,000-69,000, 47,000-50,000, 34,000-37,000, 25,000-28,000 and 14,000-16,000. The 6th fraction probably represented labeled lipids. The electrophoresis of radioiodinated seminal plasma proteins revealed only 2 radioactive protein peaks which coincided with the sperm surface protein fractions IV and V.