Histochemical and biochemical observations on milk-fat-globule membranes from several mammalian species

A specific secretory product of the lactating mammary gland are triglyceride fat globules which are enveloped by a very complex membrane, the milk fat globule membrane (MFGM). In different mammalian species (man, rhesus monkey, horse, goat, sheep, cow, grey seal, camel, alpaka) the glycoproteins of this membrane have been analyzed by gel electrophoresis, Western blotting and lectin histochemistry. A remarkable intra- and interspecific variability of these glycoproteins has been detected pointing to so far unknown physiological adaptions, which may play a role in the intestine of the new born. High molecular weight glycoproteins, with a very high degree of glycosilation have been found only in primates, horse and camel; the MFGMs of the true ruminants (cow, sheep, goat) are characterized by specific glycoproteins of a lower molecular weight range.