Which Aldolase isoenzyme is predominantly found in skeletal muscle?

• A. Aldolase A
• B. Aldolase B
• C. Aldolase C
• D. Aldolase D

Answer: (A)

Glycolytic enzymes have tissue-specific isoforms, allowing different tissues to optimize glycolysis for their needs. In skeletal muscle, the dominant isoform is Aldolase A, encoded by ALDOA. This isoform is specialized for the high, rapid glycolytic flux required during muscle contraction, helping split fructose-1,6-bisphosphate into glyceraldehyde-3-phosphate and dihydroxyacetone phosphate to fuel ATP production. Aldolase B is mainly found in liver and kidney, Aldolase C in brain, and there isn’t a standard Aldolase D isoform in humans. So the muscle-preferred isoenzyme is Aldolase A.