1,720,984 research outputs found
A comparative structural analysis of the central (fifth) pore of aquaporins: electrostatic features suggest different conductance properties for different aquaporin subfamilies
No full textAquaporins (AQPs) are homotetrameric channel proteins allowing the diffusion of water/small solutes across membranes. AQP structures are very similar, with each monomer defining a single pore selective to water/solutes and contributing to form a fifth central pore, whose meaning remains elusive. Nevertheless, AQPs show distinct transport selectivity to water, orthodox AQPs, or glycerol/solutes, aquaglyceroporins. The variety of available AQP 3D-structures is a valuable resource for studying the structure-function relationships within this protein family. A recent comparative analysis allowed specific electrostatic profiles to be associated with the main AQP selectivity to water and glycerol. We exploited this approach to gain some insights into the role of the AQP central pore. Interestingly: the electrostatics of AQP central channels correlates with their main transport function; AQP1 and AQP4 fifth pore has strikingly comparable electrostatics, supporting previous works reporting its involvement in the transport of CO2 across membranes; the central pore of the spinach PIP2;1 shares the same electrostatic profile of the monomeric pore of orthodox AQPs, suggesting that the fifth pore could allegedly represent an alternative/additional path for the transport of water across (at least some) plant AQPs. The hypothesis is being verified experimentally
Neuronal nicotinic receptor agonists: multi-approach pharmacophore development and 3D-QSAR predictive models,
No full textPoreLogo: a new tool to analyse, visualise and compare channels in transmembrane proteins
No full textFolding In Lipid Membranes (FILM): a novel method for the prediction of small membrane protein 3D structures
No full textNeuronal nicotinic acetylcholine receptor agonists: Pharmacophores, evolutionary QSAR and 3D-QSAR models
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Study of aquaporins functional diversity by comparative analysis of their sequences and structures
No full textMutations at key pore-lining positions differentiate the water permeability of fish lens aquaporin from other vertebrates
No full textAbstractAquaporin-0 (AQP0) is the major integral membrane protein of lens fiber cell and helps to maintain lens transparency by mediating inter-cell adhesion. To shed light on the unexpected higher water transport efficiency of killifish AQP0 as compared to mammalian orthologues, we performed a comparative analysis of all available AQP0 sequences and built 3D-models for representatives of different vertebrate classes.The analysis shows that air-living organisms evolved specific mutations at pore-lining positions to modulate the AQP0 water transport efficiency while maintaining the correct tertiary/quaternary arrangement to allow the formation of “thin junctions” between lens fiber cells. We conclude that the low permeability of mammalian AQP0 is required not to promote cell adhesion, but to modulate the water balance in a dry environment
3D-QSAR models and docking studies of reversible inhibitors of type A and B Monoamine Oxidases
No full textInsights into functional diversity of aquaporins by comparative analysis of their sequences and structures
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