Reconstitution of (Na+ + K+)-ATPase proteoliposomes having the same turnover rate as the membranous enzyme

Yoda, Atsunobu; Clark, Allen W.; Yoda, Shizuko

doi:10.1016/0005-2736(84)90377-8

Cited by 29 publications

(9 citation statements)

References 18 publications

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“…Converting the specific activity (/mg protein) to molecular activity (/molecule of enzyme), using the specific activity of 32-37 mmoles P/min/mg protein for ''purified'' enzyme [Jorgensen, 1974], we obtain $60 molecules ATP/s/molecule enzyme. The quantitative agreement with the enzyme turnover number [Yoda et al, 1984] is fortuitous, but the fact that electric fields do not increase the activity appreciably above this point (see Fig. 1) could indicate that the turnover number reflects the maximum concentration of charges that can be sustained in this protein.…”

Section: Estimating the Number Of Charges In The Nak-atpasementioning

confidence: 78%

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Do electromagnetic fields interact with electrons in the Na,K‐ATPase?

Blank

2005

Bioelectromagnetics

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The effects of low frequency electric and magnetic fields on several biochemical systems, including the Na,K-ATPase, indicate that electromagnetic (EM) fields interact with electrons. The frequency optima for two enzymes in response to EM fields are very close to their turnover numbers, suggesting that these interactions directly affect reaction rates. Nevertheless, generally accepted ideas about Na,K-ATPase function and ion transport mechanisms do not consider interactions with electrons. To resolve the clash of paradigms, we hypothesize interaction with transient electrons and protons that arise from flickering of H-bonds in the hydrated protein. These transient charges in the enzyme could provide a trigger for the sequence of conformation changes that are part of the ion transport mechanism. If the distributions of transient electrons and protons in the membrane are affected by their concentration and the membrane potential, as expected from electric double layer theory, this can account for the different effects of low frequency electric and magnetic fields, as well as for the observation that membrane hyperpolarization reverses the ATPase reaction to generate ATP.

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Section: Estimating the Number Of Charges In The Nak-atpasementioning

confidence: 78%

“…Further studies have shown that the frequency optimum in the response to EM fields is very close to the Na,K-ATPase turnover number [Yoda et al, 1984]. This has also been shown for cytochrome oxidase.…”

Section: Electric and Magnetic Field Effects On Nak-atpase Activitymentioning

confidence: 88%

Do electromagnetic fields interact with electrons in the Na,K‐ATPase?

Blank

2005

Bioelectromagnetics

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“…new approach to produce magnetically orientable phospholipid bilayers useful for NMR experiments (Sanders et al, 1993;Sanders and Prestegard, 1990). Both Chaps and Chapso have been used in reconstitution studies and some reports appeared in the literature dealing with the formation of active proteoliposomes (Yoda et al, 1984;Helmke and Howard, 1987). Surprisingly, however, despite all the studies that employed Chaps and Chapso, very little information is available that quantitatively characterizes the solubilization and reconstitution processes using these detergents.…”

Section: -~-mentioning

confidence: 99%

“…These non-ionic detergents have gained widespread use in solubilization and reconstitution of proteins in the last ten years. In particular, they are suitable detergents for the solubilization of many functionally active proteins (Yoda et al, 1984;Helmke and Howard, 1987;Klein and Fahrenholz, 1994;Hjelmeland, 1980;Simonds et al, 1980;Capponi et al, 1983;Soloff and Fernstrom, 1987;Dickey et al, 1987;Gould et al, 1981; Schiirholz et al, 1992). They have also been used to perturb the membrane structure, providing a R,,,, Re,, at the onset of the lamellar-to-micellar transition ; R,,>,, Re,, at complete solubilization.…”

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confidence: 99%

Liposome Solubilization and Membrane Protein Reconstitution Using Chaps and Chapso

Cladera

Ricaud

Verde

et al. 1997

European Journal of Biochemistry

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The processes of liposome solubilization and reconstitution of two transport proteins have been studied using Chaps and Chapso (3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-l-propanesulfonate). The solubilization of unilamellar liposomes was followed by absorption experiments and the process was shown to fit well to the three-stage model previously proposed for other detergents. The solubilization parameters have been determined and the detergent to phospholipid ratios at which the lamellarto-micellar transition initiates and ends were estimated to be 0.21 mol/mol and 0.74 mol/mol, for Chapso and 0.4 mol/mol and 1.04 m o l h o l for Chaps, respectively. The best conditions for the incorporation of two membrane proteins, bacteriorhodopsin and the H+-ATP synthase from chloroplasts, were analyzed at each step of the solubilization process. After detergent removal, the activities of the resulting proteoliposomes were measured indicating that the most efficient reconstitutions were obtained by addition of the proteins to completely solubilized lipid-detergent micelles. The use of Chapso and Chaps for membrane protein reconstitution studies provides a reproducible method of achieving active proteoliposomes, homogeneous in size. with a low permeability and thus, well suited for transport measurements.Keywords: 3-~(3-cholamidopropyl)dimethylammonio]-2-hydroxy-l-propanesulfonate (Chapso); Chaps; reconstitution ; proteoliposome.Structural and functional studies of membrane proteins have made important advances during the past decade. However, in many instances, these studies are still limited due to the lack of reproducible methods for the solubilization, reconstitution and/ or crystallization steps. This bottleneck is mainly related to the amphiphilic character of these membrane proteins which requires the use of detergents. Therefore, a comprehensive survey of the use and the physico-chemical properties of detergents is still needed.Chapso and Chaps are cholic acid derivatives in which the carboxylic acid has been amidated with the zwitterionic amino sulfonic acid moiety. Thus, both detergents retain the same hydrophobichydrophilic topology as the rest of the bile salts series except that they are formally neutral. These non-ionic detergents have gained widespread use in solubilization and reconstitution of proteins in the last ten years. In particular, they are suitable detergents for the solubilization of many functionally active proteins (Yoda et al., 1984;Helmke and Howard, 1987;Klein and Fahrenholz, 1994;Hjelmeland, 1980;Simonds et al., 1980;Capponi et al., 1983;Soloff and Fernstrom, 1987;Dickey et al., 1987;Gould et al., 1981; Schiirholz et al., 1992). They have also been used to perturb the membrane structure, providing a R,,,, Re,, at the onset of the lamellar-to-micellar transition ; R,,>,, Re,, at complete solubilization.

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“…EMF can accelerate certain dynamic chemical systems (like oxidation of malonic acid in the oscillating BelousovZhabotinski reaction) [Blank and Soo, 2001] or activities of enzymes such as cytochrome oxidase [Blank and Soo 1998a, 1998b, 2001, 2003 and Na + /K + -ATPase [Yoda et al, 1984;Blank, 2005]. For both enzymes, the frequency optimum in the response to EMF is very close to the en-zyme turnover number indicating that the EMF interact with components critical for determining reaction rates.…”

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confidence: 99%

Effects of Electromagnetic Fields on Cells: Physiological and Therapeutical Approaches and Molecular Mechanisms of Interaction

Funk

Monsees²

2006

Cells Tissues Organs

143

104

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This review concentrates on findings described in the recent literature on the response of cells and tissues to electromagnetic fields (EMF). Models of the causal interaction between different forms of EMF and ions or biomolecules of the cell will be presented together with our own results in cell surface recognition. Naturally occurring electric fields are not only important for cell-surface interactions but are also pivotal for the normal development of the organism and its physiological functions. A further goal of this review is to bridge the gap between recent cell biological studies (which, indeed, show new data of EMF actions) and aspects of EMF-based therapy, e.g., in wounds and bone fractures.

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Reconstitution of (Na+ + K+)-ATPase proteoliposomes having the same turnover rate as the membranous enzyme

Cited by 29 publications

References 18 publications

Do electromagnetic fields interact with electrons in the Na,K‐ATPase?

Do electromagnetic fields interact with electrons in the Na,K‐ATPase?

Liposome Solubilization and Membrane Protein Reconstitution Using Chaps and Chapso

Effects of Electromagnetic Fields on Cells: Physiological and Therapeutical Approaches and Molecular Mechanisms of Interaction

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