Characterization of glycolipid galactosyltransferases from embryonic chicken brain
Glycolipid galactosyltransferases (GalT-3 and GalT-4) were solubilized from a membrane fraction isolated from embryonic chicken brain. The profiles of specific activity and total units per brain of GalT-3 and GalT-4 varied with embryonic age. GalT-4 had the highest specific activity at 9 days of embryonic development and showed a steady decrease until hatching. GalT-3 showed a gradual increase in specific activity. Both GalT3 and GalT-4 showed a steady increase in total units per brain throughout embryonic development. The solubilized enzymes could be separated using gel filtration, ion exchange chromatography or affinity chromatography on ..cap alpha..-lactalbumin-agarose. Data obtained in the study imply that GalT-4 is involved in both glycoprotein and glycolipid biosynthesis. Glycosphingolipid products from GalT-3 and GalT-4 catalyzed reactions labeled with (/sup 14/C)galactose comigrated with authentic GMI and nLcOse/sub 4/Cer, when examined by thin layer chromatography and autoradiography. Studies with galactosidases revealed that all of the enzyme products formed by GalT-3 and GalT-4 contained a (/sup 14/C)-galactose in a ..beta.. anomeric linkage. Periodate oxidation studies of Gal-(/sup 14/C)GlcNAc, formed by purified GalT-4 using (/sup 14/C)GlcNAc as the acceptor, demonstrated that approximately 70% of the linkage formed was Gal..beta..1-4GlcNAc and 30% was Gal..beta..1-3GlcNAc. Studies on the susceptibility of (/sup 14/C)Gal-GlcNAc to base catalyzed ..beta..-elimination also suggested the presence of approximately 30% Gal..beta..1-3GlcNAc.
- Research Organization:
- Notre Dame Univ., IN (USA)
- OSTI ID:
- 6067863
- Resource Relation:
- Other Information: Thesis (Ph. D.)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BRAIN
ENZYME ACTIVITY
PENTOSYL TRANSFERASES
BIOCHEMICAL REACTION KINETICS
AUTORADIOGRAPHY
CARBON 14 COMPOUNDS
CHICKENS
EMBRYOS
EXPERIMENTAL DATA
THIN-LAYER CHROMATOGRAPHY
TRACER TECHNIQUES
ANIMALS
BIRDS
BODY
CENTRAL NERVOUS SYSTEM
CHROMATOGRAPHY
DATA
ENZYMES
FOWL
GLYCOSYL TRANSFERASES
INFORMATION
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
NERVOUS SYSTEM
NUMERICAL DATA
ORGANS
REACTION KINETICS
SEPARATION PROCESSES
TRANSFERASES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques