Transhydrogenase(TH) is located in the inner membrane of mitochondria, also knows as Mitochondrial
Respiratory Chain Complex VI. The enzyme catalyzes the mutual conversion of NADH+NADP+ and NAD
++NADPH, and regulate the balance between NAD (H) and NADP (H) in mitochondria. The reverse
reaction is called TH-2, which catalyzes NADPH and NAD+ to generate NADP+ and NADH.
Both NADH and NADPH have characteristic absorption peak at 340 nm, therefore, the hydrogen transfer
reaction catalyzed by TH cannot has a absorbance change at 340 nm. Replaces NAD + with 3-acetylpyridyl
adenine dinucleotide (APAD+, synthetic substrate), TH-2 can catalyzes APAD+ reduction to APADH and
the reaction product has a characteristic absorption peak at 375 nm. In this kit, the TH-2 activity is
quantified by measuring the rate of increase in light absorption at 375 nm.
Reagents and Equipment Required but Not Provided:
Spectrophotometer, water bath, desk centrifuge, water bath, adjustable transferpettor, 1 mL quartz cuvette,
mortar/homogenizer, ice and distilled water.
