Expression of plasmolemma proteins of the absorptive enterocytes of the cattle in the late fetal period

The article presents new scientific data on the expression of plasmalemma proteins of the absorptive enterocytes of the bovine intestines of five to nine months of age. In the late fetal period, 31 and 27 protein fractions of apical and basolateral membranes, respectively, were found in the plasmalemma of the jejunum intestine, which had a molecular weight of 9.6 kDa to 300 kDa. Twenty-nine protein fractions were detected in the apical membranes of five-month-old cattle enterocytes. It should be noted that protein fractions with low molecular weight (up to 24 kDa) were only 19.7 %, with molecular weights from 24 kDa to 100 kDa – 69.2 %, and fractions with molecular weights of 100 kDa and more were detected only – 11.1 % of the total number of polypeptides. Twenty-five protein fractions with a molecular weight of 9.6 to 155 kDa were found in the basolateral enterocyte membranes of five-month-old fetus. A large proportion of the detected protein fractions belonged to low molecular weight polypeptides (9.6–24 kDa – 40.26 %). Proteins with a molecular weight of 24–95 kDa – 55.2 %, with a molecular mass of 100 kDa and more were found only 4.56 %. High molecular weight proteins in the basolateral membrane of jejunum enterocytes of five-months-old cattle with a molecular weight greater than 155 kDa were not detected by electrophoresis (unlike the apical membrane). Analysis of the results of studies membranes protein of cattle enterocytes in late fetal period indicates significant changes in their polypeptide composition. In particular, in the basolateral membranes of enterocytes during the late fetal period there is a decrease in the content of low molecular weight protein fractions (3.3 times; P ≤ 0.001) and an increase in the proportion of high molecular weight. In addition, from the age of eight months, proteins with a molecular weight of 9.6–14.2 kDa and 75 kDa disappear in the basolateral membrane. Instead, proteins with a molecular weight of 300 kDa and 170-1885 kDa are appeared. In addition, in the apical membranes of enterocytes there is a significant decrease in the content of low molecular weight protein fractions and an increase in polypeptides with a molecular weight greater than 100 kDa. The appearance in the apical membranes of jejunum enterocytes of calves from eight months of age embryonic development of fractions of polypeptides with molecular weight of 24 kDa and 66 kDa, which are present until the end of the fetal period.