Probing conformational changes of proteins by quantitative second-derivative infrared spectroscopy.

Academic Article

Abstract

  • Probing protein conformational changes plays a crucial role in protein structure and function studies. However, the lack of efficient biophysical techniques makes it difficult to obtain the distinct behaviors of different secondary structure elements in a protein upon perturbation. This paper presents a discussion of the two major problems, the effect of sidelobes and different half-width at half-height (HWHH) values, encountered in quantitative second-derivative infrared (QSD-IR) spectroscopy and introduces the development of two criteria for checking the validity of the results obtained using the QSD-IR method. It was found that neither the sidelobes nor the HWHH significantly affected the quantitative result of protein conformational changes by using poly-l-lysine and hemoglobin as model proteins. A case study of bovine serum albumin (BSA) thermal aggregation suggested that the thermal transition of BSA was a process involving sequential events, and the two helical components were found to have a distinct response to heat perturbation. These results were confirmed by two-dimensional infrared correlation spectroscopy and by results in literature, suggesting that the QSD-IR method might be a potentially powerful tool to probe the distinct response of different secondary structures to perturbation.
  • Authors

    Keywords

  • Animals, Cattle, Protein Conformation, Protein Denaturation, Reproducibility of Results, Serum Albumin, Bovine, Spectrophotometry, Infrared, Spectroscopy, Fourier Transform Infrared, Temperature
  • Digital Object Identifier (doi)

    Author List

  • Zhang J; Yan Y-B
  • Start Page

  • 89
  • End Page

  • 98
  • Volume

  • 340
  • Issue

  • 1