Use of fructose-2,6-diphosphate to assay for phosphofructokinase activity in human muscle

✍ Scribed by Louis H. Schliselfeld; Moris J. Danon

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 496 KB
• Volume: 29
• Category: Article
• ISSN: 0009-9120
• DOI: 10.1016/0009-9120(95)02005-5

✦ Synopsis

Objective: Use fructose-2,6-diphosphate (fru-2,6-P2) for measuring phosphofructokinase (PFK) activity in muscles. Design and Methods: PFK activity was measured at 2 mmol/L MgCI2 and 5 mmol/L adenosine triphosphate (ATP) (mol/L MgCI2:mol/L ATP 0.4) without and with fru-2,6-P 2. Results: Human muscle extracts had little PFK activity when assayed at mol/L MgCI2:mol/L ATP of 0.4 to 0.78 without fru-2,6-P2; 1.83 --0.91 units/g muscle. Addition of fru-2,6-P2 produced an immediate 20-to 57-fold increase in activity; 52.8 _ 12.5 units/g muscle. Raising the mol/L ratio of MgCI 2 to ATP to 0.87 and higher without fru-2,6-P;: produced 34%-76% of the PFK activity seen with fru-2,6-P2. A PFK deficiency patient had a trace of activity, which was independent of mol/L MgCI2:mol/L ATP and not activated by fru-2,6-P2. Conclusion: The almost complete absence of activity without fru-2,6-P2 at 0.40 mol/L MgCI2:mol/L ATP, and the restoration of maximum activity by fru-2,6-P 2 provides an assay for verified PFK activity that could lead to a more accurate diagnosis in patients with PFK deficiency.