Monitoring in vivo protein-protein interactions by coupling bimolecular fluorescence complemetation (BIFC) and flow cytometry

Comunicaciones a congreso

Dual inhibitors of amyloid-β and tau aggregation with amyloid-β disaggregating properties : extended in cellulo, is Silico, and kinetic studies of multifunctional anti-Alzheimers agents

[Image: see text] In Alzheimer’s disease, neurons slowly degenerate due to the accumulation of misfolded amyloid β and tau proteins. In our research, we performed extended studies directed at amyloid β and tau aggregation inhibition using in cellulo (Escherichia coli model of protein aggregation), in silico, and in vitro kinetic studies. We tested our library of 1-benzylamino-2-hydroxyalkyl multifunctional anti-Alzheimer’s agents and identified very potent dual aggregation inhibitors. Among the tested derivatives, we selected compound 18, which exhibited a unique profile of biological activity. This compound was the most potent and balanced dual aggregation inhibitor (Aβ(42) inhibition (inh.) 80.0%, tau inh. 68.3% in 10 μM), with previously reported in vitro inhibitory activity against hBuChE, hBACE1, and Aβ (hBuChE IC(50) = 5.74 μM; hBACE1 IC(50) = 41.6 μM; Aβ aggregation (aggr.) inh. IC(50) = 3.09 μM). In docking studies for both proteins, we tried to explain the different structural requirements for the inhibition of Aβ vs tau. Moreover, docking and kinetic studies showed that compound 18 could inhibit the amyloid aggregation process at several steps and also displayed disaggregating properties. These results may help to design the next generations of dual or selective aggregation inhibitors

Native Structure Protects SUMO Proteins from Aggregation into Amyloid Fibrils

SUMO proteins belong to the Ubiquitin-like protein family, all sharing a common fold and a similar mechanism of conjugation to target polypeptides. SUMO is ubiquitous in all eukaryotes and participates in many crucial pathways. Native SUMO proteins are highly soluble, a property that is exploited in biotechnology. Moreover, SUMO regulates the solubility of aggregation-prone proteins in neurodegenerative disorders. Despite these properties, we show here that human SUMO1, SUMO2, and SUMO3 proteins are at risk of aggregation into amyloid structures if their native conformation is perturbed. Aggregation is mediated by specific regions, which overlap with SUMO functional interfaces, illustrating a competition between function and aggregation. Aggregation of SUMOs might have important physiological implications because disruption of the SUMO pathway is lethal in different organisms. It appears that functional constraints make it difficult to avoid the competition between productive folding and deleterious aggregation in globular proteins, even for essential polypeptides

New cyclopentaquinoline and 3,5-dichlorobenzoic acid hybrids with neuroprotection against oxidative stress for the treatment of Alzheimers disease

Alzheimer’s disease (AD) is a progressive neurodegenerative brain disease. Thus, drugs including donepezil, rivastigmine, and galantamine are not entirely effective in the treatment of this multifactorial disease. The present study evaluates eight derivatives (3a–3h) as candidates with stronger anti-AD potential but with less side effects. Reactive oxygen species (ROS) assays were used to assess oxidative stress which involve in the neurodegeneration. The neuroprotective properties of 3e against oxidative stress were done in three experiments using MTT test. The anti-AD potential was determined based on their anticholinesterase inhibition ability, determined using Ellman’s method, Aβ aggregation potential according to thioflavin (Th) fluorescence assay, and their antioxidative and anti-inflammatory activities. Compound 3e exhibited moderate cholinesterase inhibition activity (AChE, IC(50) = 0.131 µM; BuChE, IC(50) = 0.116 µM; SI = 1.13), significant inhibition of Aβ(1–42) aggregation (55.7%, at 5 µM) and acceptable neuroprotective activity. Extensive analysis of in vitro and in vivo assays indicates that new cyclopentaquinoline derivatives offer promise as candidates for new anti-AD drugs