Aromatic Cluster Sensor of Protein Folding Near-UV Electronic Circular Dichroism Bands Assigned to Fold Compactness /
Both far- and near-UV electronic circular dichroism (ECD) spectra have bands sensitive to thermal unfolding of Trp and Tyr residues containing proteins. Beside spectral changes at 222nm reporting secondary structural variations (far-UV range), Lb bands (near-UV range) are applicable as 3D-fold senso...
Elmentve itt :
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| Dokumentumtípus: | Cikk |
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VCH Publishers
2016
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| Sorozat: | CHEMISTRY-A EUROPEAN JOURNAL
22 No. 39 |
| doi: | 10.1002/chem.201602455 |
| mtmt: | 3101105 |
| Online Access: | http://publicatio.bibl.u-szeged.hu/10452 |
| Tartalmi kivonat: | Both far- and near-UV electronic circular dichroism (ECD) spectra have bands sensitive to thermal unfolding of Trp and Tyr residues containing proteins. Beside spectral changes at 222nm reporting secondary structural variations (far-UV range), Lb bands (near-UV range) are applicable as 3D-fold sensors of protein's core structure. In this study we show that both Lb(Tyr) and Lb(Trp) ECD bands could be used as sensors of fold compactness. ECD is a relative method and thus requires NMR referencing and cross-validation, also provided here. The ensemble of 204 ECD spectra of Trp-cage miniproteins is analysed as a training set for "calibrating" Trp↔Tyr folded systems of known NMR structure. While in the far-UV ECD spectra changes are linear as a function of the temperature, near-UV ECD data indicate a non-linear and thus, cooperative unfolding mechanism of these proteins. Ensemble of ECD spectra deconvoluted gives both conformational weights and insight to a protein folding↔unfolding mechanism. We found that the Lb 293 band is reporting on the 3D-structure compactness. In addition, the pure near-UV ECD spectrum of the unfolded state is described here for the first time. Thus, ECD folding information now validated can be applied with confidence in a large thermal window (5≤T≤85°C) compared to NMR for studying the unfolding of Trp↔Tyr residue pairs. In conclusion, folding propensities of important proteins (RNA polymerase II, ubiquitin protein ligase, tryptase-inhibitor etc.) can now be analysed with higher confidence. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. |
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| Terjedelem/Fizikai jellemzők: | 13871-13883 |
| ISSN: | 0947-6539 |