Galactosyl transferase assay. Application to experimental atherosclerosis

Area of Science:

• Biochemistry
• Vascular Biology
• Enzymology

Background:

• Aortic galactosyl transferase plays a role in collagen modification.
• Understanding its activity is crucial for studying vascular health.
• Previous assays lacked reproducibility for consistent measurement.

Purpose of the Study:

• To establish a reproducible assay for measuring aortic collagen galactosyl transferase activity.
• To investigate the effects of chronic lathyric intoxication and hypercholesterolemic diet on this enzyme activity in rabbits.

Main Methods:

• Developed an acellular biosynthesis assay using collagen as an exogenous acceptor.
• Optimized reaction conditions including substrate concentrations, Mn++ ions, temperature (37°C), and pH (7.75).
• Measured galactosyl transferase activity in rabbit aortic walls following chronic lathyric intoxication (BAPN) and/or hypercholesterolemic diet.

Main Results:

• A reproducible assay for aortic collagen galactosyl transferase was successfully established.
• Enzymatic activity significantly increased in rabbits subjected to chronic treatment.
• The increase in activity was directly proportional to the duration of the combined BAPN and cholesterolemic diet treatment.

Conclusions:

• The developed assay allows for reproducible measurement of aortic collagen galactosyl transferase.
• Combined lathyric intoxication and hypercholesterolemia elevate aortic galactosyl transferase activity.
• This elevation suggests a potential role for this enzyme in the pathogenesis of diet- and toxin-induced vascular changes.