Pharmaceutica Analytica Acta

Abstract

Thermal Fourier Transform Infrared Technique Quickly Detects an Early Onset of Glycation-Induced Conformational Changes of Human Serum Albumin

Yu-Ting Huang, Hui-Fen Liao, Shun-Li Wang and Shan-Yang Lin

Numerous potential inhibitors for prevention of advanced glycation end products (AGEs) formation have been extensively investigated for their in vitro and in vivo features, but it would spend a lot of time studying. In the present study, a unique thermal Fourier Transform Infrared (FTIR) combined system as an accelerated method was attempted to simultaneously determine the thermal-dependent conformational changes of human serum albumin (HSA) in the HSA-ribose mixture and examine the onset of the structural transformation from α-helix to β-sheet structures with or without AGEs inhibitors used. The present results clearly indicate that native HSA had an onset temperature at 96°C for the irreversible thermal-induced structural transition from α-helices to β-sheets, whereas HSA-ribose mixture exhibited its onset temperature near at 78°C due to the early occurrence of glycation. However, the onset temperature of the α-helix to β-sheet transition was gradually changed from 78°C to 96°C by increasing the amount of sodium diclofenac or inositol, which was closed to that of the onset temperature of native HSA. This implies that the thermal-induced transition from α-helix to β-sheet for HSA in the HSA-ribose mixture was effectively prevented after adding sodium or inositol. The present study also suggests that this thermal FTIR technique not only rapidly accelerates the conformational changes of HSA-ribose mixture but also directly detects onset temperature of the α-helix to β-sheet transition in real time. This unique thermal FTIR combined system could be a useful tool to screen and evaluate quickly the glycation-induced conformational changes of proteins in a one-step process.