2 research outputs found
Fragment-Based Identification of a Locus in the Sec7 Domain of Arno for the Design of ProteinâProtein Interaction Inhibitors
By virtual screening using a fragment-based
drug design (FBDD)
approach, 33 fragments were selected within small pockets around interaction
hot spots on the Sec7 surface of the nucleotide exchange factor Arno,
and then their ability to interfere with the Arno-catalyzed nucleotide
exchange on the G-protein Arf1 was evaluated. By use of SPR, NMR,
and fluorescence assays, the direct binding of three of the identified
fragments to Arno Sec7 domain was demonstrated and the promiscuous
aggregate behavior evaluated. Then the binding mode of one fragment
and of a more active analogue was solved by X-ray crystallography.
This highlighted the role of stable and transient pockets at the Sec7
domain surface in the discovery and binding of interfering compounds.
These results provide structural information on how small organic
compounds can interfere with the Arf1-Arno Sec7 domain interaction
and may guide the rational drug design of competitive inhibitors of
Arno enzymatic activity
Determination of Multimodal Isotopic Distributions: The Case of a <sup>15</sup>N Labeled Protein Produced into Hairy Roots
Isotopic labeling is widely used
in various fields like proteomics,
metabolomics, fluxomics, as well as in NMR structural studies, but
it requires an efficient determination of the isotopic enrichment.
Mass spectrometry is the method of choice for such analysis. However,
when complex expression systems like hairy roots are used for production,
multiple populations of labeled proteins may be obtained. If the isotopic
incorporation determination is actually well-known for unimodal distributions,
the multimodal distributions have scarcely been investigated. Actually,
only a few approaches allow the determination of the different labeled
population proportions from multimodal distributions. Furthermore,
they cannot be used when the number of the populations and their respective
isotope ratios are unknown. The present study implements a new strategy
to measure the <sup>15</sup>N labeled populations inside a multimodal
distribution knowing only the peptide sequence and peak intensities
from mass spectrometry analyses. Noteworthy, it could be applied to
other elements, like carbon and hydrogen, and extended to a larger
range of biomolecules