7NXI
PAF-D19S in 50 v/v % DMSO-water solution
Summary for 7NXI
| Entry DOI | 10.2210/pdb7nxi/pdb |
| NMR Information | BMRB: 34612 |
| Descriptor | Pc24g00380 protein (1 entity in total) |
| Functional Keywords | disulphide protein, paf d19s mutant, solution structure, structure from cyana 2.1, antimicrobial protein |
| Biological source | Penicillium rubens (strain ATCC 28089 / DSM 1075 / NRRL 1951 / Wisconsin 54-1255) (Penicillium chrysogenum) |
| Total number of polymer chains | 1 |
| Total formula weight | 6235.09 |
| Authors | Czajlik, A.,Batta, G. (deposition date: 2021-03-18, release date: 2022-03-30, Last modification date: 2024-11-13) |
| Primary citation | Czajlik, A.,Batta, A.,Kerner, K.,Fizil, A.,Hajdu, D.,Raics, M.,Kover, K.E.,Batta, G. DMSO-Induced Unfolding of the Antifungal Disulfide Protein PAF and Its Inactive Variant: A Combined NMR and DSC Study. Int J Mol Sci, 24:-, 2023 Cited by PubMed Abstract: PAF and related antifungal proteins are promising antimicrobial agents. They have highly stable folds around room temperature due to the presence of 3-4 disulfide bonds. However, unfolded states persist and contribute to the thermal equilibrium in aqueous solution, and low-populated states might influence their biological impact. To explore such equilibria during dimethyl sulfoxide (DMSO)-induced chemical unfolding, we studied PAF and its inactive variant PAF using nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). According to the NMR monitoring at 310 K, the folded structures disappear above 80 /% DMSO concentration, while the unfolding is completely reversible. Evaluation of a few resolved peaks from viscosity-compensated N-H HSQC spectra of PAF yielded ∆G = 23 ± 7 kJ/M as the average value for NMR unfolding enthalpy. The NMR-based structures of PAF and the mutant in 50 /% DMSO/HO mixtures were more similar in the mixed solvents then they were in water. The N NMR relaxation dynamics in the same mixtures verified the rigid backbones of the NMR-visible fractions of the proteins; still, enhanced dynamics around the termini and some loops were observed. DSC monitoring of the T melting point showed parabolic dependence on the DMSO molar fraction and suggested that PAF is more stable than the inactive PAF. The DSC experiments were irreversible due to the applied broad temperature range, but still suggestive of the endothermic unfolding of PAF. PubMed: 36674720DOI: 10.3390/ijms24021208 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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