Real-time monitoring of mitochondrial adenosine 5′ -triphosphate synthesis and hydrolysis by surface infrared spectroscopy

We have developed a method for in situ real-time monitoring of adenosine 5′ -triphosphate (ATP) synthesis in mitochondria using infrared absorption spectroscopy with the multiple internal reflection geometry. Spectral changes corresponding to ATP synthesis and hydrolysis were monitored under oxygenation and constant stirring condition. It was demonstrated that the reversible process of ATP synthesis in mitochondria can be monitored by analyzing stretching modes of α - and β- PO 2- in adenine nucleotides. Our method has potential to evaluate mitochondrial toxicity in terms of mitochondrial activities of ATP synthesis and hydrolysis.