Aldolase A

Aldolase A

The aldolase reaction catalyzed by Aldolase A.

Aldolase A is an enzyme that plays a crucial role in the glycolysis pathway, which is the metabolic pathway that converts glucose into pyruvate, releasing energy in the form of ATP. Aldolase A is one of the three isozymes of aldolase, the others being Aldolase B and Aldolase C.

Structure and Function

Aldolase A is a homotetramer, meaning it is composed of four identical subunits. Each subunit contains an active site that catalyzes the reversible cleavage of fructose 1,6-bisphosphate into two three-carbon products: dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (G3P). This reaction is a key step in glycolysis, facilitating the breakdown of glucose for energy production.

Tissue Distribution

Aldolase A is predominantly found in muscle tissue, where it is involved in the rapid production of energy during muscle contraction. It is also present in other tissues, including the brain and red blood cells, but at lower levels compared to muscle tissue.

Clinical Significance

Deficiencies in Aldolase A can lead to a rare genetic disorder known as glycogen storage disease type XII (GSD XII), which is characterized by muscle weakness and hemolytic anemia. This condition arises due to the impaired ability to efficiently metabolize glucose, leading to energy deficits in muscle cells and the destruction of red blood cells.

Biochemical Pathway

In the glycolytic pathway, Aldolase A functions after the phosphorylation of fructose 6-phosphate to fructose 1,6-bisphosphate by phosphofructokinase. The products of the aldolase reaction, DHAP and G3P, are further metabolized to generate ATP and NADH, which are essential for cellular energy.

Related Pages

• Glycolysis
• Aldolase B
• Aldolase C
• Fructose 1,6-bisphosphate
• Glycogen storage disease type XII