[Properties of alpha-1,4 leads to -glucosyltransferase from the muscles and blood serum of horses].

This research paper investigates the properties of the enzyme Alpha-1,4-glucosyltransferase extracted from horse muscle and blood serum, discovering that it functions optimally at pH 5.0, works only with substrates that have alpha-1,4-linkages, and that both enzymes exhibit hydrolytic activity at low substrate levels and transferase reactions at higher substrate concentrations.

Description of Enzyme Proteins

• The scientists focused on alpha-1,4-glucosyltransferase enzyme proteins found in the muscles and blood serum of horses.
• The research showed that these enzyme proteins found in both tissues exhibit remarkable similarities. They both have a molecular weight of 240,000 and are comprised of four subunits, each weighing 60,000 daltons.

Optimal pH Level and Reaction Conditions

• The team discovered the enzyme’s optimal functioning level to be at pH 5.0.
• Notably, only substrates with alpha-1, 4-linkages can serve as glucosyl donors for the transferase reactions- the biochemical process catalyzed by the enzyme.

Difference and Similarities in Enzyme Kms

• The Km measures the substrate concentration at which enzyme activity is half its maximal value. Despite the similarities between the two enzymes pulled from muscle and serum, the paper indicates their Km values are marginally different.

Activity at Different Substrate Concentrations

• The research points to notable changes in enzyme activity depending on the concentration of the substrate. At low substrate concentrations, the enzyme exhibited hydrolytic activity- this implies that decompositions are catalyzed by the enzyme when substrate levels are low.
• When the substrate concentration is higher than 40 mM, the enzyme only catalyzes transferase reactions. This indicates a shift from a possible decomposition activity to its primary function of catalyzing the transfer of a glucosyl group from the substrate at higher concentration levels.