[A study of the protein composition of the zona pellucida of mammalian oocytes and zygotes by a method of microelectrophoresis in polyacrylamide gel].

Z. pellucide from oocytes and zygotes of CBA mice and albino rats were lysed in a microvolume of 1% buffered sodium dodecylsulphate (SDS). The microlysate (about 1,0--2,0-10(-7) g protein) was fractionated by means microdiscelectrophoretic technique, using 10%- and 15%-polyacrylamide gel containing 0.1% SDS. The new proteins with increased anodic mobility was found among zonal proteins after fertilization in CBA mice and rats. Homogenous fraction of glycoprotein (approximately molecular weight 44 000) is found in z. pellucida of rat oocytes. This glycoprotein fraction from rat zygote coats produces 3 components moving to anode under electrophoresis. The data obtained support the hypothesis that the mechanism of "zonal fraction" under fertilization in mammals can be due to partial lysis of coat proteins by proteinase of cortical granules.