Effect of tartaric acid on conformation and stability of human prostatic phosphatase: An infrared spectroscopic and calorimetric study

The solution structure and thermal stability of human prostatic acid phosphatase (hPAP) in the absence and in the presence of tartaric acid were studied by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The temperature dependence of the infrared spectrum and DSC scans indicate that hPAP undergoes thermal unfolding at a temperature between 49.5 and 52.5°C. Binding of tartaric acid does not lead tomajor changes in the secondary structure of hPAP, however, hPAP with bound tartaric acid shows a significantly increased thermal stability. These results helped to better understand themechanismof hPAP unfolding at the elevated temperature.