Pressure- and temperature-induced unfolding and aggregation of recombinant human interferon-gamma: a Fourier transform infrared spectroscopy study.

Abstract

The effect of hydrostatic pressure on the secondary structure of recombinant human interferon-gamma (rhIFN-gamma) and its biologically inactive truncated form rhIFN-Delta C15 has been studied using Fourier-transform IR (FTIR) spectroscopy. In situ observation of the pressure-induced changes using the diamond anvil cell shows that the alpha-helical structure is mainly transformed into disordered structure at high pressure. Increasing pressure also induces the formation of a gel. Addition of 0.5 M MgCl(2) significantly reduces the pressure stability. Releasing the pressure below 300 MPa results in the formation of intermolecular antiparallel beta-sheets, which is seldom observed. This suggests that the intermolecular beta-sheet of rhIFN-gamma is stabilized by electrostatic interactions that are disrupted at high pressure. For comparison we also studied the effect of temperature. Temperature-induced changes reflect extensive transformation of alpha-helical structure into intermolecular antiparallel beta-sheet, as is usually observed for most proteins.

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Cite this paper

@article{Goossens2003PressureAT, title={Pressure- and temperature-induced unfolding and aggregation of recombinant human interferon-gamma: a Fourier transform infrared spectroscopy study.}, author={Koen Goossens and Joost Haelewyn and Filip Meersman and Marc De Ley and Karel Heremans}, journal={The Biochemical journal}, year={2003}, volume={370 Pt 2}, pages={529-35} }