CERM research published in Nature
Affinity gradients drive copper to cellular destinations |
A group of CERM researchers has determined, through a unified electrospray ionization mass spectrometry (ESI-MS)-based strategy, in an environment that mimics the cellular redox milieu, the apparent Cu(I)-binding affinities for a representative set of intracellular copper proteins involved in enzymatic redox catalysis, in copper trafficking to and within various cellular compartments, and in copper storage. The resulting thermodynamic data show that copper is drawn to the enzymes that require it by passing from one copper protein site to another, exploiting gradients of increasing copper-binding affinity.
Please click here for the link to the article. |
Hot off the Press:
Ultrafast MAS solid-state NMR permits extensive (13)C and (1H) detection in paramagnetic metalloproteins
We show here that by combining tailored approaches based on ultrafast (60 kHz) MAS on the Co(II)-replaced catalytic domain of matrix metalloproteinase 12 (CoMMP-12) we can observe and assign, in a highly paramagnetic protein in the solid state, (13)C and even (1)H resonances from the residues coordinating the metal center. In addition, by exploiting the enhanced relaxation caused by the paramagnetic center, and the low power irradiation enabled by the fast MAS, this can be achieved in remarkably short times and at very high field (21.2 T), with only less than 1 mg of sample. Furthermore, using the known crystal structure of the compound, we are able to distinguish and measure pseudocontact (PCS) contributions to the shifts up to the coordinating ligands and to unveil structural information. Please click here for the link to the article
New drug design proceeds
thanks to the Monte dei Paschi di Siena Foundation
The research project "Identifying ligands and binding sites on pharmacological target proteins for future new drug design" financed by the Monte dei Paschi di Siena Foundation focuses on the development of small-molecule modulators of protein-protein interactions, using NMR spectroscopy to monitor small-molecule binding to the two proteins of pharmaceutical relevance, S100B and Bcl-xL. NMR-based identification of the hot spots on the protein surfaces relies on the use of Garrett plots that provide chemical shift mapping of the protein residues involved in the interaction. This structural information, in conjunction with estimates of the Kd and ligand efficiency values, will provide the basis for further ligand optimization. The project is expected to have significant impact on the discovery of novel therapeutics.
This study has recently been accepted for publication in Chembiochem: "Fragmenting the S100B-p53 interaction - Combined virtual/biophysical screening approaches to identify ligands", by Alessandro Padova
High-resolution solid-state NMR structure of a 17.6 kDa protein solved
As recently published in the Journal of the American Chemical Society, pseudocontact shifts arising from paramagnetic metal ions in a microcrystalline protein sample have been used to obtain unambiguous signal assignments in solid-state NMR spectra, enabling distance extraction for protein structure calculation. The resulting structure is high-resolution and in good agreement with the X-ray structure. This strategy may be generalized for non-metalloproteins through the use of paramagnetic tags, and represents a significant step ahead in protein structure determination using solid-state NMR. Please click here for the link to the article.
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