An enzymatic method for the assay of serum argininosuccinate lyase

✍ Scribed by Toshiaki Miura; Megumi Kashiwamura; Michiya Kimura

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 474 KB
• Volume: 164
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(87)90522-7

✦ Synopsis

A rapid enzymatic method was developed for the assay of serum argininosuccinate lyase (ASAL: EC 4.3.2.1) which is a useful marker enzyme for diagnosis of parenchymal liver diseases. Fumarate, liberated from argininosuccinate in the lyase-mediated reaction, was converted to pyruvate via L-malate by the actions of fumarase and malic enzyme in the presence of NADP'. The NADPH formed was then oxidized with a diaphorase-resazurin system to give a highly fluorescent resorufin. All the enzymatic reactions proceeded continuously in 0.1 M Tris-HCl buffer (pH 7.5) and allowed direct assay of ASAL in serum by monitoring the increase in the fluorescence intensity due to resorufin. The method is rapid and sensitive; only 50 pl of serum is required. This method was used to detect increases in the activities in sera from patients with liver diseases.