This manuscript describes a MATLAB program devoted to the analysis of relaxation data obtained at... more This manuscript describes a MATLAB program devoted to the analysis of relaxation data obtained at different values of magnetic induction B0. Using Reduced Spectral Density Mapping (based on the High-Frequency Approximation), J(0), J(xX) and < J(xH) > are calculated from heteronuclear (15N ou 13C) R1, R2 relaxation rates and heteronuclear NOE ratio values. In order to obtain the motion parameters (correlation times and order parameters), spectral densities are then fitted with the different variants of the Lipari–Szabo model. Then, the choice of the right model can be chosen through a statistical analysis (v2, F-test). As an applica- tion, the dynamics analysis of the 15N relaxation data obtained at 9.4, 11.75 and 14.1 Tesla (corresponding to proton frequencies of 400, 500 and 600 MHz) on the protein P13MTCP1 is given.
Serine/threonine kinase Akt plays a central role in the regulation of cell survival and prolifera... more Serine/threonine kinase Akt plays a central role in the regulation of cell survival and proliferation. Hence, the search for Akt specific inhibitors constitutes an attractive strategy for anticancer therapy. We have previously demonstrated that the proto-oncogene TCL1 coactivates Akt upon binding to its Plekstrin Homology Domain, and we proposed a model for the structure of the complex TCL1:Akt2-PHD. This model led to the rational design of Akt-in, a peptide inhibitor spanning the A ß-strand of human TCL1 that binds Akt2 PH domain and inhibits the kinase activation. In the present report, we used NMR spectroscopy to determine the 3D structure of the peptide free in solution and bound to Akt2-PHD. NMR chemical shift mapping was used to determine the imprint of Akt-in on the PH domain; whereas peptide Ala-scanning revealed which peptide residues were involved in the interaction. Together with the solution structure of Akt2-PHD, these results allowed us to dock Akt-in on the PH domain....
Cassiicolin is a host-selective toxin (HST) produced by the fungus Corynespora cassiicola (strain... more Cassiicolin is a host-selective toxin (HST) produced by the fungus Corynespora cassiicola (strain CCP). It is responsible for the Corynespora leaf fall (CLF) disease, which is among the main pathologies affecting rubber tree (Hevea brasiliensis). Working on purified cassiicolin and using electron microscopy, we have demonstrated that this 27-residue O-glycosylated protein is able to induce cellular damages identical to those induced by the fungus on rubber tree leaves and displays the same host selectivity. The solution structure and disulfide pairing of cassiicolin have been determined using NMR spectroscopy and simulated annealing calculations. Cassiicolin appears to have an original structure with a prolate ellipsoid shape. It adopts an over-all fold consisting of three strands arranged in a right-handed twisted, antiparallel beta-sheet knitted by three disulfide bonds. Its conformation resembles that found in small trypsine-like inhibitors isolated from the brain, the fat body a...
This manuscript describes a MATLAB program devoted to the analysis of relaxation data obtained at... more This manuscript describes a MATLAB program devoted to the analysis of relaxation data obtained at different values of magnetic induction B0. Using Reduced Spectral Density Mapping (based on the High-Frequency Approximation), J(0), J(xX) and < J(xH) > are calculated from heteronuclear (15N ou 13C) R1, R2 relaxation rates and heteronuclear NOE ratio values. In order to obtain the motion parameters (correlation times and order parameters), spectral densities are then fitted with the different variants of the Lipari–Szabo model. Then, the choice of the right model can be chosen through a statistical analysis (v2, F-test). As an applica- tion, the dynamics analysis of the 15N relaxation data obtained at 9.4, 11.75 and 14.1 Tesla (corresponding to proton frequencies of 400, 500 and 600 MHz) on the protein P13MTCP1 is given.
Serine/threonine kinase Akt plays a central role in the regulation of cell survival and prolifera... more Serine/threonine kinase Akt plays a central role in the regulation of cell survival and proliferation. Hence, the search for Akt specific inhibitors constitutes an attractive strategy for anticancer therapy. We have previously demonstrated that the proto-oncogene TCL1 coactivates Akt upon binding to its Plekstrin Homology Domain, and we proposed a model for the structure of the complex TCL1:Akt2-PHD. This model led to the rational design of Akt-in, a peptide inhibitor spanning the A ß-strand of human TCL1 that binds Akt2 PH domain and inhibits the kinase activation. In the present report, we used NMR spectroscopy to determine the 3D structure of the peptide free in solution and bound to Akt2-PHD. NMR chemical shift mapping was used to determine the imprint of Akt-in on the PH domain; whereas peptide Ala-scanning revealed which peptide residues were involved in the interaction. Together with the solution structure of Akt2-PHD, these results allowed us to dock Akt-in on the PH domain....
Cassiicolin is a host-selective toxin (HST) produced by the fungus Corynespora cassiicola (strain... more Cassiicolin is a host-selective toxin (HST) produced by the fungus Corynespora cassiicola (strain CCP). It is responsible for the Corynespora leaf fall (CLF) disease, which is among the main pathologies affecting rubber tree (Hevea brasiliensis). Working on purified cassiicolin and using electron microscopy, we have demonstrated that this 27-residue O-glycosylated protein is able to induce cellular damages identical to those induced by the fungus on rubber tree leaves and displays the same host selectivity. The solution structure and disulfide pairing of cassiicolin have been determined using NMR spectroscopy and simulated annealing calculations. Cassiicolin appears to have an original structure with a prolate ellipsoid shape. It adopts an over-all fold consisting of three strands arranged in a right-handed twisted, antiparallel beta-sheet knitted by three disulfide bonds. Its conformation resembles that found in small trypsine-like inhibitors isolated from the brain, the fat body a...
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