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Molecular dynamics study of the archaeal aquaporin AqpM
BACKGROUND: Aquaporins are a large family of transmembrane channel proteins that are present throughout all domains of life and are implicated in human disorders. These channels, allow the passive but selective movement of water and other small neutral solutes across cell membranes. Aquaporins have...
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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BioMed Central
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3287591/ https://www.ncbi.nlm.nih.gov/pubmed/22369250 http://dx.doi.org/10.1186/1471-2164-12-S4-S8 |
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author | Araya-Secchi, Raul Garate , JA Holmes, David S Perez-Acle, Tomas |
author_facet | Araya-Secchi, Raul Garate , JA Holmes, David S Perez-Acle, Tomas |
author_sort | Araya-Secchi, Raul |
collection | PubMed |
description | BACKGROUND: Aquaporins are a large family of transmembrane channel proteins that are present throughout all domains of life and are implicated in human disorders. These channels, allow the passive but selective movement of water and other small neutral solutes across cell membranes. Aquaporins have been classified into two sub-families: i) strict aquaporins that only allow the passage of water and ii) the less selective aquaglyceroporins that transport water and other neutral solutes, such as glycerol, CO(2) or urea. Recently, the identification and characterization of a number of archaeal and bacterial aquaporins suggested the existence of a third sub-family; one that is neither a strict aquaporin nor an aquaglyceroporin. The function and phylogeny of this third family is still a matter of debate. RESULTS: Twenty nanosecond molecular dynamics (MD) simulation of a fully hydrated tetramer of AqpM embedded in a lipid bilayer permitted predictions to be made of key biophysical parameters including: single channel osmotic permeability constant (p(f)), single channel diffusive permeability constant (p(d)), channel radius, potential water occupancy of the channel and water orientation inside the pore. These properties were compared with those of well characterized representatives of the two main aquaporin sub-families. Results show that changes in the amino acid composition of the aromatic/arginine region affect the size and polarity of the selectivity filter (SF) and could help explain the difference in water permeability between aquaporins. In addition, MD simulation results suggest that AqpM combines characteristics of strict aquaporins, such as the narrow SF and channel radius, with those of aquaglyceroporins, such as a more hydrophobic and less polar SF. CONCLUSIONS: MD simulations of AqpM extend previous evidence that this archaeal aquaporin exhibits hybrid features intermediate between the two known aquaporin sub-families, supporting the idea that it may constitute a member of a novel class of aquaporins. |
format | Online Article Text |
id | pubmed-3287591 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-32875912012-02-28 Molecular dynamics study of the archaeal aquaporin AqpM Araya-Secchi, Raul Garate , JA Holmes, David S Perez-Acle, Tomas BMC Genomics Proceedings BACKGROUND: Aquaporins are a large family of transmembrane channel proteins that are present throughout all domains of life and are implicated in human disorders. These channels, allow the passive but selective movement of water and other small neutral solutes across cell membranes. Aquaporins have been classified into two sub-families: i) strict aquaporins that only allow the passage of water and ii) the less selective aquaglyceroporins that transport water and other neutral solutes, such as glycerol, CO(2) or urea. Recently, the identification and characterization of a number of archaeal and bacterial aquaporins suggested the existence of a third sub-family; one that is neither a strict aquaporin nor an aquaglyceroporin. The function and phylogeny of this third family is still a matter of debate. RESULTS: Twenty nanosecond molecular dynamics (MD) simulation of a fully hydrated tetramer of AqpM embedded in a lipid bilayer permitted predictions to be made of key biophysical parameters including: single channel osmotic permeability constant (p(f)), single channel diffusive permeability constant (p(d)), channel radius, potential water occupancy of the channel and water orientation inside the pore. These properties were compared with those of well characterized representatives of the two main aquaporin sub-families. Results show that changes in the amino acid composition of the aromatic/arginine region affect the size and polarity of the selectivity filter (SF) and could help explain the difference in water permeability between aquaporins. In addition, MD simulation results suggest that AqpM combines characteristics of strict aquaporins, such as the narrow SF and channel radius, with those of aquaglyceroporins, such as a more hydrophobic and less polar SF. CONCLUSIONS: MD simulations of AqpM extend previous evidence that this archaeal aquaporin exhibits hybrid features intermediate between the two known aquaporin sub-families, supporting the idea that it may constitute a member of a novel class of aquaporins. BioMed Central 2011-12-22 /pmc/articles/PMC3287591/ /pubmed/22369250 http://dx.doi.org/10.1186/1471-2164-12-S4-S8 Text en Copyright ©2011 Araya-Secchi et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Proceedings Araya-Secchi, Raul Garate , JA Holmes, David S Perez-Acle, Tomas Molecular dynamics study of the archaeal aquaporin AqpM |
title | Molecular dynamics study of the archaeal aquaporin AqpM |
title_full | Molecular dynamics study of the archaeal aquaporin AqpM |
title_fullStr | Molecular dynamics study of the archaeal aquaporin AqpM |
title_full_unstemmed | Molecular dynamics study of the archaeal aquaporin AqpM |
title_short | Molecular dynamics study of the archaeal aquaporin AqpM |
title_sort | molecular dynamics study of the archaeal aquaporin aqpm |
topic | Proceedings |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3287591/ https://www.ncbi.nlm.nih.gov/pubmed/22369250 http://dx.doi.org/10.1186/1471-2164-12-S4-S8 |
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