Circular Dichrosim Studies on the Deinococcus Radiodurans Nudix Hydrolase DR_0079: an Atypical Thermal Melt
We have recently determined the solution structure of the hypothetical Deinococcus radiodurans Nudix protein DR0079 [Proteins 56:28-39]. The protein is a monomer and contains the fundamental fold common to the Nudix family, a large mixed b-sheet sandwiched between a-helices. The protein¹s physical properties were further characterized by circular dichroism (CD) spectroscopy. A CD thermal melt indicates an inflection point at ~52ºC. However, unlike typical CD thermal melts, the ellipticity at 220 nm decreases upon passing through the inflection point suggesting that the amount of secondary structure in the protein has increased after heating. NMR spectroscopy and size exclusion chromatography indicates that heating effects the irreversible formation of a large molecular weight complex. After cooling, the ellipiticity at 220 nm increases further, and overall, the CD spectrum at 25ºC shows that heat-treated DR0079 has more ³structure² than non-heat treated DR0079.
- Research Organization:
- Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 982544
- Report Number(s):
- PNNL-SA-46812; 2331a; KP1101010
- Journal Information:
- Protein and Peptide Letters, 17(7):831-835, Journal Name: Protein and Peptide Letters, 17(7):831-835 Journal Issue: 7 Vol. 17
- Country of Publication:
- United States
- Language:
- English
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