Comparison of sialylation of maltase-glucoamylase in brush-border and soluble fractions of the small intestine of immature rats.
Two fractions of high-molar-mass soluble neutral maltase-glucoamylase (G1 and G2) of distal small intestine of 18-day-old rats separated on Sepharose 4B differ in sialylation which is reflected in their pI values obtained by chromatofocusing. The major soluble G1 fraction shows eight sialylated peaks converted by neuraminidase into a single fraction eluted at pH 4.21. Fraction G2 is less sialylated and neuraminidase causes its pI shift to 4.36. The chromatofocusing pattern suggests that G1 contains more acidic and G2 more basic glycoforms than their membrane-bound counterpart. Presence of less acidic pI values in the soluble G1 fraction of 18-day-old rats than in that of 13-day-old rats indicates that developmental decrease of sialylation concerns not only membrane-bound but also the soluble membrane-type of maltase-glucoamylase.
Kolínská
J
J
Department of Membrane Transport, Czechoslovak Academy of Sciences, Prague.
Zákostelecká
M
M
Asfaw
B
B
D000818:Animals; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007421:Intestine, Small / Q000201:enzymology* / Q000648:ultrastructure; D007525:Isoelectric Focusing; D008871:Microvilli / Q000201:enzymology*; D009439:Neuraminidase / Q000378:metabolism*; D051381:Rats; D012995:Solubility; D000520:alpha-Glucosidases / Q000737:chemistry*
D009439:Neuraminidase; D000520:alpha-Glucosidases