Articles by Luiza M. Bessa in JoVE
Nuclear Magnetic Resonance Spectroscopy for the Identification of Multiple Phosphorylations of Intrinsically Disordered Proteins Clément Danis*1,2, Clément Despres*1, Luiza M. Bessa1, Idir Malki1, Hamida Merzougui1, Isabelle Huvent1, Haoling Qi1, Guy Lippens1, François-Xavier Cantrelle1, Robert Schneider1, Xavier Hanoulle1, Caroline Smet-Nocca1, Isabelle Landrieu1 1UMR8576, CNRS, Lille University, 2UMR-S1172, INSERM CNRS, Lille University We describe here a method to identify multiple phosphorylations of an intrinsically disordered protein by Nuclear Magnetic Resonance Spectroscopy (NMR), using Tau protein as a case study. Recombinant Tau is isotopically enriched and modified in vitro by a kinase prior to data acquisition and analysis.
Other articles by Luiza M. Bessa on PubMed
In Vitro and in Vivo Activity of a New Unsymmetrical Dinuclear Copper Complex Containing a Derivative Ligand of 1,4,7-triazacyclononane: Catalytic Promiscuity of [Cu2(L)Cl3] Dalton Transactions (Cambridge, England : 2003). May, 2013 | Pubmed ID: 23515486 Here we present the synthesis of the dinuclear complex [Cu(II)2(L)Cl3] (1), where L is the deprotonated form of the 3-[(4,7-diisopropyl-1,4,7-triazacyclononan-1-yl)methyl]-2-hydroxy-5-methylbenzaldehyde ligand. The complex was characterized by single crystal X-ray diffraction, potentiometric titration, mass spectrometry, electrochemical and magnetic measurements, EPR, UV-Vis and IR. Complex 1 is able to increase the hydrolysis rate of the diester bis-(2,4-dinitrophenyl)phosphate (2,4-BDNPP) by a factor of 2700, and also to promote the plasmidial DNA cleavage at pH 6 and to inhibit the formazan chromophore formation in redox processes at pH 7. Using Saccharomyces cerevisiae (BY4741) as a eukaryotic cellular model, we observed that 1 presents reduced cytotoxicity. In addition, treatment of wild-type and mutant cells lacking Cu/Zn-superoxide dismutase (Sod1) and cytoplasmic catalase (Ctt1) with 1 promotes increased survival after H2O2 or menadione (O2˙(-) generator) stress, indicating that 1 might act as a Sod1 and Ctt1 mimetic. Considered together, these results support considerations regarding the dynamic behaviour of an unsymmetrical dinuclear copper(II) complex in solid state and in aqueous pH-dependent solution.
Binding Mechanisms of Intrinsically Disordered Proteins: Theory, Simulation, and Experiment Frontiers in Molecular Biosciences. 2016 | Pubmed ID: 27668217 In recent years, protein science has been revolutionized by the discovery of intrinsically disordered proteins (IDPs). In contrast to the classical paradigm that a given protein sequence corresponds to a defined structure and an associated function, we now know that proteins can be functional in the absence of a stable three-dimensional structure. In many cases, disordered proteins or protein regions become structured, at least locally, upon interacting with their physiological partners. Many, sometimes conflicting, hypotheses have been put forward regarding the interaction mechanisms of IDPs and the potential advantages of disorder for protein-protein interactions. Whether disorder may increase, as proposed, e.g., in the "fly-casting" hypothesis, or decrease binding rates, increase or decrease binding specificity, or what role pre-formed structure might play in interactions involving IDPs (conformational selection vs. induced fit), are subjects of intense debate. Experimentally, these questions remain difficult to address. Here, we review experimental studies of binding mechanisms of IDPs using NMR spectroscopy and transient kinetic techniques, as well as the underlying theoretical concepts and numerical methods that can be applied to describe these interactions at the atomic level. The available literature suggests that the kinetic and thermodynamic parameters characterizing interactions involving IDPs can vary widely and that there may be no single common mechanism that can explain the different binding modes observed experimentally. Rather, disordered proteins appear to make combined use of features such as pre-formed structure and flexibility, depending on the individual system and the functional context.