Molecular dynamics study of the archaeal aquaporin AqpM.

摘要: Aquaporins are a large family of transmembrane channel proteins that present throughout all domains life and implicated in human disorders. These channels, allow the passive but selective movement water other small neutral solutes across cell membranes. have been classified into two sub-families: i) strict aquaporins only passage ii) less aquaglyceroporins transport solutes, such as glycerol, CO2 or urea. Recently, identification characterization number archaeal bacterial suggested existence third sub-family; one is neither aquaporin nor an aquaglyceroporin. The function phylogeny this still matter debate. Twenty nanosecond molecular dynamics (MD) simulation fully hydrated tetramer AqpM embedded lipid bilayer permitted predictions to be made key biophysical parameters including: single osmotic permeability constant (p f ), diffusive d radius, potential occupancy orientation inside pore. properties were compared with those well characterized representatives main sub-families. Results show changes amino acid composition aromatic/arginine region affect size polarity selectivity filter (SF) could help explain difference between aquaporins. In addition, MD results suggest combines characteristics aquaporins, narrow SF aquaglyceroporins, more hydrophobic polar SF. simulations extend previous evidence exhibits hybrid features intermediate known sub-families, supporting idea it may constitute member novel class