| 1. |
|
|
| 2. |
- Lanza, Nina L., et al.
(author)
-
Oxidation of manganese in an ancient aquifer, Kimberley formation, Gale crater, Mars
- 2016
-
In: Geophysical Research Letters. - 0094-8276 .- 1944-8007. ; 43:14, s. 7398-7407
-
Journal article (peer-reviewed)abstract
- The Curiosity rover observed high Mn abundances (>25wt % MnO) in fracture-filling materials that crosscut sandstones in the Kimberley region of Gale crater, Mars. The correlation between Mn and trace metal abundances plus the lack of correlation between Mn and elements such as S, Cl, and C, reveals that these deposits are Mn oxides rather than evaporites or other salts. On Earth, environments that concentrate Mn and deposit Mn minerals require water and highly oxidizing conditions; hence, these findings suggest that similar processes occurred on Mars. Based on the strong association between Mn-oxide deposition and evolving atmospheric dioxygen levels on Earth, the presence of these Mn phases on Mars suggests that there was more abundant molecular oxygen within the atmosphere and some groundwaters of ancient Mars than in the present day
|
|
| 3. |
- Lenton, Samuel, et al.
(author)
-
Effect of Phosphorylation on a Human-like Osteopontin Peptide
- 2017
-
In: Biophysical Journal. - : Elsevier BV. - 0006-3495. ; 112:8, s. 1586-1596
-
Journal article (peer-reviewed)abstract
- The last decade established that the dynamic properties of the phosphoproteome are central to function and its modulation. The temporal dimension of phosphorylation effects remains nonetheless poorly understood, particularly for intrinsically disordered proteins. Osteopontin, selected for this study due to its key role in biomineralization, is expressed in many species and tissues to play a range of distinct roles. A notable property of highly phosphorylated isoforms of osteopontin is their ability to sequester nanoclusters of calcium phosphate to form a core-shell structure, in a fluid that is supersaturated but stable. In Biology, this process enables soft and hard tissues to coexist in the same organism with relative ease. Here, we extend our understanding of the effect of phosphorylation on a disordered protein, the recombinant human-like osteopontin rOPN. The solution structures of the phosphorylated and unphosphorylated rOPN were investigated by small-angle x-ray scattering and no significant changes were detected on the radius of gyration or maximum interatomic distance. The picosecond-to-nanosecond dynamics of the hydrated powders of the two rOPN forms were further compared by elastic and quasi-elastic incoherent neutron scattering. Phosphorylation was found to block some nanosecond side-chain motions while increasing the flexibility of other side chains on the faster timescale. Phosphorylation can thus selectively change the dynamic behavior of even a highly disordered protein such as osteopontin. Through such an effect on rOPN, phosphorylation can direct allosteric mechanisms, interactions with substrates, cofactors and, in this case, amorphous or crystalline biominerals.
|
|
| 4. |
|
|
| 5. |
- Palmer, BF, et al.
(author)
-
Clinical Management of Hyperkalemia
- 2021
-
In: Mayo Clinic proceedings. - : Elsevier BV. - 1942-5546 .- 0025-6196. ; 96:3, s. 744-762
-
Journal article (peer-reviewed)
|
|
