Title: Comparative Fourier transform infrared spectroscopy study of cold-, pressure-, and heat-induced unfolding and aggregation of myoglobin
Authors: Meersman, Filip ×
Smeller, L
Heremans, Karel #
Issue Date: Jan-2002
Publisher: Biophysical society
Series Title: Biophysical Journal vol:82 issue:5 pages:2635-2644
Abstract: We studied the cold unfolding of myoglobin with Fourier transform infrared spectroscopy and compared it with pressure and heat unfolding. Because protein aggregation is a phenomenon with medical as well as biotechnological implications, we were interested in both the structural changes as well as the aggregation behavior of the respective unfolded states. The cold- and pressure-induced unfolding both yield a partially unfolded state characterized by a persistent amount of secondary structure, in which a stable core of G and H helices is preserved. In this respect the cold- and pressure-unfolded states show a resemblance with an early folding intermediate of myoglobin. In contrast, the heat unfolding results in the formation of the infrared bands typical of intermolecular antiparallel beta-sheet aggregation. This implies a transformation of alpha-helix into intermolecular beta-sheet. H/H-2-exchange data suggest that the helices are first unfolded and then form intermolecular beta-sheets. The pressure and cold unfolded states do not give rise to the intermolecular aggregation bands that are typical for the infrared spectra of many heat-unfolded proteins. This suggests that the pathways of the cold and pressure unfolding are substantially different from that of the heat unfolding. After return to ambient conditions the cold- or pressure-treated proteins adopt a partially refolded conformation. This aggregates at a lower temperature (32degreesC) than the native state (74degreesC).
ISSN: 0006-3495
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Molecular Imaging and Photonics
Biochemistry, Molecular and Structural Biology Section
× corresponding author
# (joint) last author

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