Aldolaasin

Aldolaasin is a collective term for a group of enzymes that catalyze aldol reactions or aldol cleavage reactions. In biochemistry, the aldol reaction is a carbon-carbon bond forming reaction that occurs between an enol or enolate ion and a carbonyl compound. The aldol cleavage reaction is the reverse of this process, breaking a carbon-carbon bond. Enzymes that catalyze these reactions are crucial in many metabolic pathways, particularly in carbohydrate metabolism.

The most well-known aldolase enzyme is fructose-1,6-bisphosphate aldolase, which plays a key role in glycolysis and gluconeogenesis. This enzyme facilitates the reversible cleavage of fructose-1,6-bisphosphate into two three-carbon molecules: dihydroxyacetone phosphate and glyceraldehyde-3-phosphate. This step is a critical regulatory point in glucose metabolism. There are different types of aldolases, classified based on their reaction mechanism and the substrates they act upon. Class I aldolases, found in animals and plants, use a Schiff base intermediate with their substrate. Class II aldolases, found in fungi and bacteria, require a metal ion cofactor, typically zinc, to catalyze the reaction. The specific aldolase present in an organism and its isoforms can influence metabolic flux and contribute to cellular regulation.