Characterization of E-PHA-reactive alpha-fetoprotein isoforms by two-dimensional lectin affinity electrophoresis

Electrophoresis. 1993 Dec;14(12):1333-7. doi: 10.1002/elps.11501401205.

Abstract

Erythroagglutinating phytohemagglutinin (E-PHA)-dependent isoforms of human alpha-fetoprotein (AFP) from cord blood were analyzed for their carbohydrate structures by two-dimensional electrophoresis with E-PHA combined with extended agarose gel electrophoresis or with affinity electrophoresis with concanavalin A or Allomyrina dichtoma lectin. By means of neuraminidase and/or beta-galactosidase treatment, AFP-P2 was identified as alpha 2-->6 disialo-AFP, AFP-P3 as having biantennary structures with alpha 2-->6 monosialylated galactose of the Mannose (Man) alpha 1-->6 arm, AFP-P4 as having alpha 2-->6 monosialylated galactose of the Man alpha 1-->3 arm, and AFP-P5 as disialo-AFP with alpha 2-->3 sialylated galactose of the Man alpha 1-->6 antenna with the alpha 2-->6 sialylated galactose of the other antenna. Desialylated AFP with the terminal galactose of the Man alpha 1-->6 antenna with or without the galactose of the other arm also had a migration of AFP-P4, and other hydrolytic intermediates without the terminal galactose of the Man alpha 1-->6 arm with and without the galactose of the other antenna had mobilities of AFP-P3s and AFP-P3, respectively. Thus, the present system of two-dimensional lectin affinity electrophoreses would provide a model for the determination of the sugar chain structure of glycoproteins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Conformation
  • Carbohydrate Sequence
  • Concanavalin A
  • Electrophoresis, Agar Gel
  • Electrophoresis, Gel, Two-Dimensional*
  • Fetal Blood / chemistry*
  • Molecular Sequence Data
  • Molecular Structure
  • Neuraminidase / pharmacology
  • Phytohemagglutinins*
  • alpha-Fetoproteins / analysis*
  • alpha-Fetoproteins / chemistry
  • beta-Galactosidase / pharmacology

Substances

  • Phytohemagglutinins
  • alpha-Fetoproteins
  • erythroagglutinating phytohemagglutinin
  • Concanavalin A
  • Neuraminidase
  • beta-Galactosidase