Cooperative unfolding of apolipoprotein A-1 induced by chemical denaturation

Eckhardt, D. and Li-Blatter, X. and Schönfeld, H.-J. and Heerklotz, H. and Seelig, J.. (2018) Cooperative unfolding of apolipoprotein A-1 induced by chemical denaturation. Biophysical chemistry, 240. pp. 42-49.

Full text not available from this repository.

Official URL: https://edoc.unibas.ch/72727/

Downloads: Statistics Overview


Apolipoprotein A-1 (Apo A-1) plays an important role in lipid transfer and obesity. Chemical unfolding of α-helical Apo A-1 is induced with guanidineHCl and monitored with differential scanning calorimetry (DSC) and CD spectroscopy. The unfolding enthalpy and the midpoint temperature of unfolding decrease linearly with increasing guanidineHCl concentration, caused by the weak binding of denaturant. At room temperature, binding of 50-60 molecules guanidineHCl leads to a complete Apo A-1 unfolding. The entropy of unfolding decreases to a lesser extent than the unfolding enthalpy. Apo A-1 chemical unfolding is a dynamic multi-state equilibrium that is analysed with the Zimm-Bragg theory modified for chemical unfolding. The chemical Zimm-Bragg theory predicts the denaturant binding constant K; D; and the protein cooperativity σ. Chemical unfolding of Apo A-1 is two orders of magnitude less cooperative than thermal unfolding. The free energy of thermal unfolding is ~0.2 kcal/mol per amino acid residue and ~1.0 kcal/mol for chemical unfolding at room temperature. The Zimm-Bragg theory calculates conformational probabilities and the chemical Zimm-Bragg theory predicts stretches of α-helical segments in dynamic equilibrium, unfolding and refolding independently and fast.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Former Organization Units Biozentrum > Biophysical Chemistry (Seelig J)
UniBasel Contributors:Seelig, Joachim
Item Type:Article, refereed
Article Subtype:Research Article
Note:Publication type according to Uni Basel Research Database: Journal article
Identification Number:
Last Modified:05 Apr 2020 13:48
Deposited On:05 Apr 2020 13:48

Repository Staff Only: item control page