The Experts below are selected from a list of 261 Experts worldwide ranked by ideXlab platform
Kiaran Kirk - One of the best experts on this subject based on the ideXlab platform.
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Membrane Transport in the malaria parasite and its host erythrocyte.
The Biochemical journal, 2013Co-Authors: Kiaran Kirk, Adele M. LehaneAbstract:As it grows and replicates within the erythrocytes of its host the malaria parasite takes up nutrients from the extracellular medium, exports metabolites and maintains a tight control over its internal ionic composition. These functions are achieved via Membrane Transport proteins, integral Membrane proteins that mediate the passage of solutes across the various Membranes that separate the biochemical machinery of the parasite from the extracellular environment. Proteins of this type play a key role in antimalarial drug resistance, as well as being candidate drug targets in their own right. This review provides an overview of recent work on the Membrane Transport biology of the malaria parasite-infected erythrocyte, encompassing both the parasite-induced changes in the Membrane Transport properties of the host erythrocyte and the cell physiology of the intracellular parasite itself.
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Membrane Transport proteins of the malaria parasite
Molecular microbiology, 2009Co-Authors: Rowena E. Martin, Hagai Ginsburg, Kiaran KirkAbstract:Summary The malaria parasite-infected erythrocyte is a multi-compartment structure, incorporating numerous different Membrane systems. The movement of nutrients, metabolites and inorganic ions into and out of the intraerythrocytic parasite, as well as between subcellular compartments within the parasite, is mediated by Transporters and channels – integral Membrane proteins that facilitate the movement of solutes across the Membrane bilayer. Proteins of this type also play a key role in antimalarial drug resistance. Genes encoding Transporters and channels account for at least 2.5% of the parasite genome. However, ascribing functions and physiological roles to these proteins, and defining their roles in drug resistance, is not straightforward. For any given Membrane Transport protein, a full understanding of its role(s) in the parasitized erythrocyte requires a knowledge of its subcellular localization and substrate specificity, as well as some knowledge of the effects on the parasite of modifying the sequence and/or level of expression of the gene involved. Here we consider recent work in this area, describe a number of newly identified Transport proteins, and summarize the likely subcellular localization and putative substrate specificity of all of the candidate Membrane Transport proteins identified to date.
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Plasmodium permeomics: Membrane Transport proteins in the malaria parasite.
Current topics in microbiology and immunology, 2005Co-Authors: Kiaran Kirk, Rowena E. Martin, Stefan Bröer, Susan M. Howitt, Kevin J. SalibaAbstract:Membrane Transport proteins are integral Membrane proteins that mediate the passage across the Membrane bilayer of specific molecules and/or ions. Such proteins serve a diverse range of physiological roles, mediating the uptake of nutrients into cells, the removal of metabolic wastes and xenobiotics (including drugs), and the generation and maintenance of transMembrane electrochemical gradients. In this chapter we review the present state of knowledge of the Membrane Transport mechanisms underlying the cell physiology of the intraerythrocytic malaria parasite and its host cell, considering in particular physiological measurements on the parasite and parasitized erythrocyte, the annotation of Transport proteins in the Plasmodium genome, and molecular methods used to analyze Transport protein function.
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NMR methods for measuring Membrane Transport
Sub-cellular biochemistry, 1994Co-Authors: Philip W. Kuchel, Kiaran Kirk, Glenn F. KingAbstract:The aim of this chapter is to outline the reasons why certain items of information are sought for a description of Membrane Transport, to describe the various types of NMR experiment that can be used to obtain estimates of the rates of Membrane Transport, and to illustrate the various NMR procedures with biological examples. The major appeal of the NMR method in this context lies in the fact that the measurements do not usually require the physical separation of the cells or vesicles from their suspending solution. The work described here is a subset of the large number of NMR studies that have been carried out in recent years on living systems (for reviews see Shulman, 1979; Gadian and Radda, 1981; Kuchel, 1981, 1989; Gadian, 1982; Avison et al., 1986; Cerdan and Seelig, 1990; Lundberg et al., 1990). NMR studies of Membrane Transport have recently been reviewed (Kirk, 1990; Kuchel, 1990; King and Boyd, 1991); the first two reviews are directed mostly at “NMR audiences” and the latter to “biological audiences.” It is the intention that this chapter might be useful to readers who are NMR experts as well as those who are not; the latter may be encouraged to try the NMR counterparts of more conventional experiments and the former may find something of interest in these newer applications of NMR spectroscopy.
Tamotsu Kondo - One of the best experts on this subject based on the ideXlab platform.
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Further studies on Membrane Transport with time delay
Biophysical chemistry, 1991Co-Authors: Hiroyuki Ohshima, Miki Kamei, Tamotsu KondoAbstract:A theory of cell Membrane Transport with a time delay which predicts under certain conditions overshoot or oscillatory permeation (Ohshima and Kondo, Biophys. Chem. 33 (1989) 303), is extended with the introduction of a parameter expressing a fraction of solutes inside the cell interior that suffer time delay. It is found that criterion for oscillation depends strongly on this parameter. Results will also be presented for the case of an exponential-type distribution of the delay time.
B. Baranowski - One of the best experts on this subject based on the ideXlab platform.
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Non-equilibrium thermodynamics as applied to Membrane Transport
Journal of Membrane Science, 1991Co-Authors: B. BaranowskiAbstract:The framework of linear non-equilibrium thermodynamics (LNET) has been briefly characterized, tracing the way of derivation of the phenomenological equations. Applications to Membrane Transport phenomena have been presented in two-, three- and four-flow approaches. The treatment of active Transport in terms of LNET is given. The reduction to Nernst-Einstein equations is briefly outlined, and the experimental verification of Onsager reciprocal relations as well as more general applications to experimental results are reviewed. Furthermore, the importance of individual balance equations for the coupling of diffusion and viscous phenomena is presented. The importance of this approach is also illustrated for the generalization of Prigogine's theorem for invariance of the diffusional entropy production. Possible non-local phenomena due to stress fields are indicated and generalized advantages and disadvantages of the thermodynamic treatment are summarized. As an example of a more general approach to Membrane Transport, extended non-equilibrium thermodynamics, ENET, is briefly presented. © 1991.
Philip W. Kuchel - One of the best experts on this subject based on the ideXlab platform.
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NMR magnetization-transfer analysis of rapid Membrane Transport in human erythrocytes
Biophysical reviews, 2016Co-Authors: Dmitry Shishmarev, Philip W. KuchelAbstract:Nuclear magnetic resonance (NMR) magnetization-transfer (MT) experiments provide a convenient tool for studying rapid sub-second Membrane-Transport processes in situ in metabolically active cells. These experiments are used with Membrane-permeable substances when separate (resolved) NMR signals are observed from their populations inside and outside the cells. Here, we provide a description of the theory and practice of the most common NMR MT experiments that have been used to study Membrane-Transport processes in human erythrocytes (red blood cells; RBCs). The procedures, involved in the analysis of the experimental data for defining mechanisms of Transport, and for estimating values of kinetic parameters in the corresponding mathematical models, are given special attention.
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NMR methods for measuring Membrane Transport
Sub-cellular biochemistry, 1994Co-Authors: Philip W. Kuchel, Kiaran Kirk, Glenn F. KingAbstract:The aim of this chapter is to outline the reasons why certain items of information are sought for a description of Membrane Transport, to describe the various types of NMR experiment that can be used to obtain estimates of the rates of Membrane Transport, and to illustrate the various NMR procedures with biological examples. The major appeal of the NMR method in this context lies in the fact that the measurements do not usually require the physical separation of the cells or vesicles from their suspending solution. The work described here is a subset of the large number of NMR studies that have been carried out in recent years on living systems (for reviews see Shulman, 1979; Gadian and Radda, 1981; Kuchel, 1981, 1989; Gadian, 1982; Avison et al., 1986; Cerdan and Seelig, 1990; Lundberg et al., 1990). NMR studies of Membrane Transport have recently been reviewed (Kirk, 1990; Kuchel, 1990; King and Boyd, 1991); the first two reviews are directed mostly at “NMR audiences” and the latter to “biological audiences.” It is the intention that this chapter might be useful to readers who are NMR experts as well as those who are not; the latter may be encouraged to try the NMR counterparts of more conventional experiments and the former may find something of interest in these newer applications of NMR spectroscopy.
Hiroyuki Ohshima - One of the best experts on this subject based on the ideXlab platform.
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Further studies on Membrane Transport with time delay
Biophysical chemistry, 1991Co-Authors: Hiroyuki Ohshima, Miki Kamei, Tamotsu KondoAbstract:A theory of cell Membrane Transport with a time delay which predicts under certain conditions overshoot or oscillatory permeation (Ohshima and Kondo, Biophys. Chem. 33 (1989) 303), is extended with the introduction of a parameter expressing a fraction of solutes inside the cell interior that suffer time delay. It is found that criterion for oscillation depends strongly on this parameter. Results will also be presented for the case of an exponential-type distribution of the delay time.