Search results for "molten globule"
showing 6 items of 6 documents
Direct observation of alpha-lactalbumin, adsorption and incorporation into lipid membrane and formation of lipid/protein hybrid structures
2019
The interaction between proteins and membranes is of great interest in biomedical and biotechnological research for its implication in many functional and dysfunctional processes. We present an experimental study on the interaction between model membranes and alpha-lactalbumin (alpha-La). alpha-La is widely studied for both its biological function and its anti-tumoral properties. We use advanced fluorescence microscopy and spectroscopy techniques to characterize alpha-La-membrane mechanisms of interaction and alpha-La-induced modifications of membranes when insertion of partially disordered regions of protein chains in the lipid bilayer is favored. Moreover, using fluorescence lifetime imag…
Local dynamic properties of the heme pocket in native and solvent-induced molten-globule-like states of cytochrome c
2002
We report the Soret absorption band, down to cryogenic temperature, of native and molten-globule-like state of horse heart cytochrome c. The band profile is analyzed in terms of vibronic coupling of the heme normal modes to the electronic transition in the framework of the Franck-Condon approximation. From the temperature dependence of the Gaussian broadening and of the peak position, we obtain information on the 'bath' of low frequency harmonic motions of the heme group within the heme pocket. The reported data indicate that, compared to the native state, the less rigid tertiary structure of the molten globule is reflected in a higher flexibility of the heme pocket and in greater conformat…
Decoding the Folding of Burkholderia glumae Lipase: Folding Intermediates En Route to Kinetic Stability
2012
The lipase produced by Burkholderia glumae folds spontaneously into an inactive near-native state and requires a periplasmic chaperone to reach its final active and secretion-competent fold. The B. glumae lipase-specific foldase (Lif) is classified as a member of the steric-chaperone family of which the propeptides of alpha-lytic protease and subtilisin are the best known representatives. Steric chaperones play a key role in conferring kinetic stability to proteins. However, until present there was no solid experimental evidence that Lif-dependent lipases are kinetically trapped enzymes. By combining thermal denaturation studies with proteolytic resistance experiments and the description of…
New set of 2D/3D thermodynamic indices for proteins. A formalism based on "Molten Globule" theory
2010
Abstract We define eight new macromolecular indices, and several related descriptors for proteins. The coarse grained methodology used for its deduction ensures its fast execution and becomes a powerful potential tool to explore large databases of protein structures. The indices are intended for stability studies, predicting Φ -values, predicting folding rate constants, protein QSAR/QSPR as well as protein alignment studies. Also, these indices could be used as scoring function in protein-protein docking or 3D protein structure prediction algorithms and any others applications which need a numerical code for proteins and/or residues from 2D or 3D format.
Interactions entre la beta-lactoglobuline et les arômes : impact au niveau moléculaire
2008
Interactions between β-lactoglobulin (BLG) and aroma compounds were investigated by complementary techniques for a better knowledge of binding mechanisms between proteins and aroma compounds at a molecular scale. Two binding sites have been defined for the monomeric BLG, one internal site within the central calyx, and one external site between the calyx and the α helix. In a first step, a relation between the ligand structure and its binding behaviour was established from the study of impact of a wide range of aroma compounds on the structure of native BLG. We evidenced at least two binding behaviours as a function of the chemical class, the hydrophobicity, or the structure of the ligands. …
Interactions between aroma compounds and beta-lactoglobulin in the heat-induced molten globule state
2010
; he present study aims to elucidate the binding of small hydrophobic ligands onto the molten globule state of β-lactoglobulin (BLG). The conversion of the native BLG into a molten globule state was induced by heat treatment at acidic pH. The molten globule state was evidenced by far and near-UV circular dichroism spectra. β-Ionone and guaiacol exhibited a higher binding ability to BLG in the heat-induced molten globule state compared to unheated BLG, as assessed by protein surface hydrophobicity measurements, using 6-propionyl-2-(dimethylamino)naphthalene (PRODAN) fluorescent probe. The binding sites of the two aroma compounds were determined by 2D nuclear magnetic resonance (NMR) spectro…