Conformational dynamics and interfacial interactions of peptide-appended pillar[5]arene water channels in biomimetic membranes

2019 ◽  
Vol 21 (41) ◽  
pp. 22711-22721 ◽  
Author(s):  
Yong Liu ◽  
Harish Vashisth
Keyword(s):  
Water Purification ◽  
Conformational Dynamics ◽  
Water Channel ◽  
Water Channels ◽  
Interfacial Interactions ◽  
Biomimetic Membranes ◽  
Channel Proteins ◽  
Significant Potential ◽  
Biological Water ◽  
Artificial Water

Peptide appended pillar[5]arene (PAP) is an artificial water channel resembling biological water channel proteins, which has shown a significant potential for designing bioinspired water purification systems.

Design Considerations for Artificial Water Channel–Based Membranes

2018 ◽  
Vol 48 (1) ◽  
pp. 57-82 ◽  
Author(s):  
Woochul Song ◽  
Chao Lang ◽  
Yue-xiao Shen ◽  
Manish Kumar
Keyword(s):  
Historical Perspective ◽  
Water Channel ◽  
Water Channels ◽  
Structure And Properties ◽  
High Permeability ◽  
Functional Elements ◽  
Design Considerations ◽  
Biological Water ◽  
Naturally Occurring ◽  
Artificial Water

Aquaporins (AQPs) are naturally occurring water channel proteins. They can facilitate water molecule translocation across cellular membranes with exceptional selectivity and high permeability that are unmatched in synthetic membrane systems. These unique properties of AQPs have led to their use as functional elements in membranes in recent years. However, the intricate nature of AQPs and concerns regarding their stability and processability have encouraged researchers to develop synthetic channels that mimic the structure and properties of AQPs and other biological water-conducting channels. These channels have been termed artificial water channels. This article reviews current progress and provides a historical perspective as well as an outlook toward developing scalable membranes based on artificial water channels.

scholarly journals Bioinspired and biomimetic membranes for water purification and chemical separation: A review

2021 ◽  
Vol 15 (6) ◽  
Author(s):  
Elham Abaie ◽  
Limeimei Xu ◽  
Yue-xiao Shen
Keyword(s):  
Transport Properties ◽  
Large Scale ◽  
Water Channel ◽  
Chemical Separation ◽  
Molecular Engineering ◽  
Research Progress ◽  
Biomimetic Membranes ◽  
Separation Membranes ◽  
Biological Water ◽  
Transport Channels

AbstractBioinspired and biomimetic membranes that contain biological transport channels or attain their structural designs from biological systems have been through a remarkable development over the last two decades. They take advantage of the exceptional transport properties of those channels, thus possess both high permeability and selectivity, and have emerged as a promising solution to existing membranes. Since the discovery of biological water channel proteins aquaporins (AQPs), extensive efforts have been made to utilize them to make separation membranes-AQP-based membranes, which have been commercialized. The exploration of AQPs’ unique structures and transport properties has resulted in the evolution of biomimetic separation materials from protein-based to artificial channel-based membranes. However, large-scale, defect-free biomimetic membranes are not available yet. This paper reviews the state-of-the-art biomimetic membranes and summarizes the latest research progress, platform, and methodology. Then it critically discusses the potential routes of this emerging area toward scalable applications. We conclude that an appropriate combination of bioinspired concepts and molecular engineering with mature polymer industry may lead to scalable polymeric membranes with intrinsic selective channels, which will gain the merit of both desired selectivity and scalability.

scholarly journals Aquaporins: A Multidisciplinary Perspective on The Water Channel Proteins

Acta Medica ◽  
2020 ◽  
Vol 51 (2) ◽  
pp. 30-42
Author(s):  
Gokce Alp ◽  
Iffet Ipek Bosgelmez ◽  
Yesim Oztas
Keyword(s):  
Cell Proliferation ◽  
Cell Migration ◽  
Water Channel ◽  
High Water ◽  
Point Of View ◽  
Biomimetic Membranes ◽  
Channel Proteins ◽  
Recent Developments ◽  
Osmotic Balance ◽  
Multidisciplinary Perspective

Aquaporins are unique water channel proteins located at cell membranes that possess high water permeability and high solute rejection. Their primary function is to maintain the osmotic balance of the cells via regulating the water transport. However, their discovery had also provided the scientists to understand the pathophysiology of some diseases. In fact, aquaporins are shown to be strongly related to cancer by taking part in several tumor-related processes such as cell migration, cell proliferation and cell adhesion. Other than their functions in human body, recently, aquaporins have started to be used in engineering biomimetic membranes, for different applications such as desalination. This review investigates the properties and functions of the aquaporins in a multidisciplinary point of view and demonstrates the recent developments in aquaporin-based research.

scholarly journals The energetic barrier to single-file water flow through narrow channels

2021 ◽  
Author(s):  
Juergen Pfeffermann ◽  
Nikolaus Goessweiner-Mohr ◽  
Peter Pohl
Keyword(s):  
Lipid Bilayers ◽  
Degrees Of Freedom ◽  
Water Channel ◽  
Water Channels ◽  
Bulk Water ◽  
State Theory ◽  
Narrow Channels ◽  
Biological Water ◽  
Free Energy Of Activation ◽  
Single File

AbstractVarious nanoscopic channels of roughly equal diameter and length facilitate single-file diffusion at vastly different rates. The underlying variance of the energetic barriers to transport is poorly understood. First, water partitioning into channels so narrow that individual molecules cannot overtake each other incurs an energetic penalty. Corresponding estimates vary widely depending on how the sacrifice of two out of four hydrogen bonds is accounted for. Second, entropy differences between luminal and bulk water may arise: additional degrees of freedom caused by dangling OH-bonds increase entropy. At the same time, long-range dipolar water interactions decrease entropy. Here, we dissect different contributions to Gibbs free energy of activation, ΔG‡, for single-file water transport through narrow channels by analyzing experimental results from water permeability measurements on both bare lipid bilayers and biological water channels that (i) consider unstirred layer effects and (ii) adequately count the channels in reconstitution experiments. First, the functional relationship between water permeabilities and Arrhenius activation energies indicates negligible differences between the entropies of intraluminal water and bulk water. Second, we calculate ΔG‡ from unitary water channel permeabilities using transition state theory. Plotting ΔG‡ as a function of the number of H-bond donating or accepting pore-lining residues results in a 0.1 kcal/mol contribution per residue. The resulting upper limit for partial water dehydration amounts to 2 kcal/mol. In the framework of biomimicry, our analysis provides valuable insights for the design of synthetic water channels. It thus may aid in the urgent endeavor towards combating global water scarcity.

scholarly journals Artificial Water Channels: Towards Biomimetic Membranes for Desalination

2020 ◽  
Author(s):  
Li‐Bo Huang ◽  
Maria Di Vincenzo ◽  
Yuhao Li ◽  
Mihail Barboiu
Keyword(s):  
Water Channels ◽  
Biomimetic Membranes ◽  
Artificial Water

scholarly journals Water channel pore size determines exclusion properties but not solute selectivity

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Philip Kitchen ◽  
Mootaz M. Salman ◽  
Simone U. Pickel ◽  
Jordan Jennings ◽  
Susanna Törnroth-Horsefield ◽  
...  
Keyword(s):  
Pore Size ◽  
In Silico ◽  
Water Channel ◽  
Water Channels ◽  
Selectivity Filter ◽  
Single Amino Acid ◽  
Cross Sectional ◽  
Solute Permeability ◽  
Channel Proteins

AbstractAquaporins (AQPs) are a ubiquitous family of transmembrane water channel proteins. A subgroup of AQP water channels also facilitates transmembrane diffusion of small, polar solutes. A constriction within the pore, the aromatic/arginine (ar/R) selectivity filter, is thought to control solute permeability: previous studies on single representative water channel proteins suggest narrow channels conduct water, whilst wider channels permit passage of solutes. To assess this model of selectivity, we used mutagenesis, permeability measurements and in silico comparisons of water-specific as well as glycerol-permeable human AQPs. Our studies show that single amino acid substitutions in the selectivity filters of AQP1, AQP4 and AQP3 differentially affect glycerol and urea permeability in an AQP-specific manner. Comparison between in silico-calculated channel cross-sectional areas and in vitro permeability measurements suggests that selectivity filter cross-sectional area predicts urea but not glycerol permeability. Our data show that substrate discrimination in water channels depends on a complex interplay between the solute, pore size, and polarity, and that using single water channel proteins as representative models has led to an underestimation of this complexity.

Ion/Water Channels for Embryo Implantation Barrier

Physiology ◽  
2014 ◽  
Vol 29 (3) ◽  
pp. 186-195 ◽  
Author(s):  
Xin-Mei Liu ◽  
Dan Zhang ◽  
Ting-Ting Wang ◽  
Jian-Zhong Sheng ◽  
He-Feng Huang
Keyword(s):  
Stromal Cells ◽  
Action Potentials ◽  
Steroid Hormone ◽  
Embryo Implantation ◽  
Water Channel ◽  
Water Channels ◽  
Resting Membrane Potential ◽  
Luminal Epithelium ◽  
Channel Proteins ◽  
Harmful Substances

Successful implantation involves three distinct processes, namely the embryo apposition, attachment, and penetration through the luminal epithelium of the endometrium to establish a vascular link to the mother. After penetration, stromal cells underlying the epithelium differentiate and surround the embryo to form the embryo implantation barrier, which blocks the passage of harmful substances to the embryo. Many ion/water channel proteins were found to be involved in the process of embryo implantation. First, ion/water channel proteins play their classical role in establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane. Second, most of ion/water channel proteins are regulated by steroid hormone (estrogen or progesterone), which may have important implications to the embryo implantation. Last but not least, these proteins do not limit themselves as pure channels but also function as an initiator of a series of consequences once activated by their ligand/stimulator. Herein, we discuss these new insights in recent years about the contribution of ion/water channels to the embryo implantation barrier construction during early pregnancy.

Fate of antidiuretic hormone water channel proteins after retrieval from apical membrane

1993 ◽  
Vol 265 (3) ◽  
pp. C822-C833 ◽  
Author(s):  
M. L. Zeidel ◽  
T. G. Hammond ◽  
J. B. Wade ◽  
J. Tucker ◽  
H. W. Harris
Keyword(s):  
Membrane Proteins ◽  
Antidiuretic Hormone ◽  
Apical Membrane ◽  
Water Channel ◽  
Fluid Phase ◽  
Water Channels ◽  
Endocytic Pathway ◽  
Electron Microscopic ◽  
Channel Proteins ◽  
Fluorescence Measurements

In toad bladder granular cells, antidiuretic hormone (ADH) stimulates insertion of vesicles containing water channels (WCV), markedly increasing apical membrane osmotic water permeability (Pf). After withdrawal of ADH stimulation, WCV are removed from the apical membrane and fluid-phase markers endocytosed from the apical solution appear predominantly in endosomes at 10-15 min and multivesicular bodies at 30-60 min. Although the luminal contents of this endocytic pathway have been well characterized, the fate of membrane proteins, including functional ADH water channels in these vesicles remains unclear. Using electron microscopic, flow cytometric, and stopped-flow fluorescence measurements and characterization of labeled vesicle proteins, we examined the fate of membrane proteins contained within WCV. The protein complements of endosomes harvested after 10, 30, and 60 min of ADH withdrawal were similar. Selective covalent labeling of apical proteins during ADH stimulation followed by ADH reversal for 30 or 60 min showed that apical proteins colocalize with fluid-phase marker-labeled endosomes at all times, and most apically labeled protein bands present in the 10-min fraction were also present in the 30- and 60-min endosome fractions. Endosomes at 10 and 30 min but not at 60 min contained functional water channels revealed by high Pf and proton permeability, low activation energy of Pf, and sensitivity of Pf to mercurial reagents. We conclude that a portion of apically exposed membrane proteins, including candidate water channel proteins, travel together with fluid-phase markers from 10-min endosomes into later endosomal compartments. Functional water channels may be inactivated or some essential protein component selectively sorted away between 30 and 60 min after ADH withdrawal.

scholarly journals Frontispiece: Artificial Water Channels: Towards Biomimetic Membranes for Desalination

2021 ◽  
Vol 27 (7) ◽  
Author(s):  
Li‐Bo Huang ◽  
Maria Di Vincenzo ◽  
Yuhao Li ◽  
Mihail Barboiu
Keyword(s):  
Water Channels ◽  
Biomimetic Membranes ◽  
Artificial Water

Radio and Electrical Measurements on Glacial Streams

1987 ◽  
Vol 33 (114) ◽  
pp. 239-242
Author(s):  
M. E. R. Walford
Keyword(s):  
Electrical Conductivity ◽  
Water Channel ◽  
Water System ◽  
Low Frequency ◽  
Water Channels ◽  
Radiative Loss ◽  
Radio Waves ◽  
Electrical Measurements ◽  
Water Conductivity ◽  
Glacier Surface

AbstractWe discuss the suggestion that small underwater transmitters might be used to illuminate the interior of major englacial water channels with radio waves. Once launched, the radio waves would naturally tend to be guided along the channels until attenuated by absorption and by radiative loss. Receivers placed within the channels or at the glacier surface could be used to detect the signals. They would provide valuable information about the connectivity of the water system. The electrical conductivity of the water is of crucial importance. A surface stream on Storglaciären, in Sweden, was found, using a low-frequency technique, to have a conductivity of approximately 4 × 10−4 S m−1. Although this is several hundred times higher than the conductivity of the surrounding glacier ice, the contrast is not sufficient to permit us simply to use electrical conductivity measurements to establish the connectivity of englacial water channels. However, the water conductivity is sufficiently small that, under favourable circumstances, radio signals should be detectable after travelling as much as a few hundred metres along an englacial water channel. In a preliminary field experiment, we demonstrated semi quantitatively that radio waves do indeed propagate as expected, at least in surface streams. We conclude that under-water radio transmitters could be of real practical value in the study of the englacial water system, provided that sufficiently robust devices can be constructed. In a subglacial channel, however, we expect the radio range would be much smaller, the environment much harsher, and the technique of less practical value.

Sign in / Sign up

Export Citation Format

Share Document