Vanadate and its significance in biochemistry and pharmacology

Erdmann, Erland; Werdan, Karl; Krawietz, W.; Schmitz, Wolfgang; Scholz, Hasso

doi:10.1016/0006-2952(84)90498-2

Cited by 78 publications

(12 citation statements)

References 53 publications

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“…The observed equilibrium constants, K , , measured at any pH are related to the pH-independent K i of Scheme 1 and the Ka2 values for vanadate and its esters by eq. [3].…”

Section: Resultsmentioning

confidence: 99%

The characterization of primary, secondary, and tertiary vanadate alkyl esters by ⁵¹V nuclear magnetic resonance spectroscopy

Tracey¹,

Gresser²

1988

Can. J. Chem.

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. Can. J . Chem. 66, 2570Chem. 66, (1988. A variety of alkyl vanadates has been studied by "V nuclear magnetic resonance spectroscopy. It was found that the equilibrium constant for condensation of vanadate with alcohols is insensitive to whether the hydroxyl group is primary, secondary, or tertiary. These products, however, have characteristic vanadium chemical shifts that allow assignment of nrnr signals to the appropriate ester. It was also found that chemical shifts are additive in the sense that the chemical shifts of the esters ROV03H-are one half the chemical shift of the diesters (RO)zV07-when those shifts are given relative to -559 ppm. This effect is independent of whether the signals are to high or low field of -559 ppm and the additivity extends to mixed ligand systems. This value of -559 ppm is close but not equal to the chemical shift of the vanadate monoanion, H~v o~' -, which is at -561 ppm. These results are at variance with arguments concerning the effects of ligand bulkiness on chemical shifts of vanadium(V) complexes. ALAN S. TRACEY et MICHAEL J. GRESSER. Can. J. Chem. 66, 2570(1988. On a CtudiC un certain nombre de vanadates d'alkyles en faisant appel a la resonance magnCtique nucltaire du "v. On a trouvC que la constante d'kquilibre pour la col~densation du vanadate avec les alcools n'est pas sensible au caractkre primaire, secondaire ou tertiaire des groupements hydroxyles. Toutefois, ces produits possedent des diplacements chimiques du vanadium qui sont caracteristiques et qui permettent d'attribuer les signaux rmn aux esters appropriCs. On a trouvC que les dCplacements chimiques sont additifs dans le sens que les dtplacements chimiques des esters ROV03H-correspondent a la moitiC des dtplacements chimiques des diesters (R0)7VOI-lorsque ces dCplacements sont donnCs par rapport a -559 ppm. Cet effet ne dCpend pas de la position de ces signaux par rapport -559 ppm et cette additivitk s'etend aux systemes comportant des ligands mixtes. La valeur de -559 ppm s'approche du. mais elle n'est pas Cgale au, dkplacement chimique du monoanion de vanadate, H2VO4'-, qui est Cgal a -561 ppm. Ces rtsultats sont en opposition avec les arguments concernant les effets d'encombrement des ligands sur les dkplacements chimiques des complexes de vanadium(V).[Traduit par la revue]

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“…The observed equilibrium constants, K , , measured at any pH are related to the pH-independent K i of Scheme 1 and the Ka2 values for vanadate and its esters by eq. [3].…”

Section: Resultsmentioning

confidence: 99%

The characterization of primary, secondary, and tertiary vanadate alkyl esters by ⁵¹V nuclear magnetic resonance spectroscopy

Tracey¹,

Gresser²

1988

Can. J. Chem.

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“…We decided to examine this possibility by using sodium vanadate, which has been shown to inhibit several ATPases [18] including rat liver microsomal Ca2+-ATPase [2] as well as microsomal Ca2 transport [19]. Sodium vanadate had no significant effect on the Mg2+-ATPase activity but CaZt uptake and Ca2+-ATPase activity were severely inhibited by sodium vanadate (data not shown).…”

Section: Resultsmentioning

confidence: 99%

The effect of Mg2+ on hepatic microsomal Ca2+ and Sr2+ transport

Fleschner¹,

Kraus‐Friedmann²

1986

Eur J Biochem

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The ATP-dependent uptake of Ca2+ by rat liver microsomal fraction is dependent upon Mg2'. Studies of the Mg2+ requirement of the underlying microsomal Ca2+-ATPase have been hampered by the presence of a large basal Mg2+-ATPase activity. We have examined the effect of various Mg2+ concentrations on Mg2 +-ATPase activity, Ca2+ uptake, Ca2+-ATPase activity and microsomal phosphoprotein formation.Both Mg2 In order to examine the apparent paradox of Mg2+ stimulation of Ca2+ uptake but not of Ca2+-ATPase activity, we examined the formation of the Ca2 +-ATPase phosphoenzyme intermediate and formation of a Mg2+-dependent phosphoprotein, which we have proposed to be an attribute of the Mg2+-ATPase activity. We found that Ca2+ apparently inhibited formation of the Mg2+-dependent phosphoprotein both in the absence and presence of exogenous Mg2 +. This suggests that Ca2+ may inhibit (at least partially) the Mg2+-ATPase activity.However, inclusion of the Ca2 + inhibition of Mg2 +-ATPase activity in the calculation of Ca2 +-ATPase activity reveals that this effect is insufficient to totally account for the stimulation of Ca2+ uptake by Mg2+. This suggests that Mg2+, in addition to stimulation of Ca2+-ATPase activity, may have a direct stimulatory effect on Ca2+ uptake in an as yet undefined fashion.In an effort to further examine the effect of Mg2+ on the microsomal Ca2+ transport system of rat liver, the interaction of this system with Sr2+ was examined. Sr2+ was sequestered into an A23187-releasable space in an ATP-dependent manner by rat liver microsomal fraction. The uptake of Sr2+ was similar to that of Ca2+ in terms of both rate and extent. A Sr2+-dependent ATPase activity was associated with the Sr2+ uptake. Sr2+ promoted formation of a phosphoprotein which was hydroxylamine-labile and base-labile. This phosphoprotein was indistinguishable from the Ca2 + -dependent ATPase phosphoenzyme intermediate. Sr2+ uptake was markedly stimulated by exogenous Mg2+, but the Sr2+-dependent ATPase activity was unaffected by increasing Mg2+ concentrations. Sr2+ uptake and %-'+-dependent ATPase activity were concomitantly inhibited by sodium vanadate.In contrast to Ca2+, Sr2+ had no effect on Mg2+-dependent phosphoprotein formation. Taken together, these data indicate that Mg2+ stimulated Ca2+ and Sr2+ transport by increasing the Ca2+(Sr2+)/ATP ratio. However, in the case of Ca2+ at least, these data must be interpreted with caution since Ca2+ may inhibit the Mg2+-ATPase activity.The ATP-dependent accumulation of Ca2+ by the rat liver microsomal fraction is now well documented. It is generally accepted that the enzymatic basis for the ATP-dependent Ca2 + accumulation is the microsomal Ca2 + -ATPase. Initially studies of this enzyme were hindered by the use of 5 mM

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“…Despite recent investigations, its physiological role for humans remains largely unclear [20]. The mean normal daily intake of vanadium has been reported by various authors as between 12-28 µg [21] or 10-100 µg [22]. The total vanadium content of the body is 0.1-0.2 mg [39].…”

Section: Vanadiummentioning

confidence: 99%

“…Studies using 48 V have shown that 77 % of the vanadium in plasma is bound to transferrin [23,24]. VO 3-has long been known as a potent inhibitor of Na + and K + ATPase (sodium pump), a common enzyme in the eukaryotic system [20,21,25]. Vanadium compounds can selectively enhance the permeability of human erythrocytes to K + [26,27].…”

Section: Vanadiummentioning

confidence: 99%

Beryllium, Lithium, Vanadium, Tungsten [Biomonitoring Methods, 1996]

Schramel¹

2012

The MAK‐Collection for Occupational Health and Safety

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Published in the series Analyses of Hazardous Substances in Biological Materials , Vol. 5 (1996) The article contains sections titled: General principles Equipment, chemicals and solutions Equipment Chemicals Solutions Calibration standards Specimen collection and sample preparation Operational parameters for emission spectrometry Analytical determination Calibration Calculation of the analytical result Standardization and quality control Reliability of the method Precision Accuracy Detection limit Sources of error Discussion of the method

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Vanadate and its significance in biochemistry and pharmacology

Cited by 78 publications

References 53 publications

The characterization of primary, secondary, and tertiary vanadate alkyl esters by ⁵¹V nuclear magnetic resonance spectroscopy

The characterization of primary, secondary, and tertiary vanadate alkyl esters by ⁵¹V nuclear magnetic resonance spectroscopy

The effect of Mg2+ on hepatic microsomal Ca2+ and Sr2+ transport

Beryllium, Lithium, Vanadium, Tungsten [Biomonitoring Methods, 1996]

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Vanadate and its significance in biochemistry and pharmacology

Cited by 78 publications

References 53 publications

The characterization of primary, secondary, and tertiary vanadate alkyl esters by 51V nuclear magnetic resonance spectroscopy

The characterization of primary, secondary, and tertiary vanadate alkyl esters by 51V nuclear magnetic resonance spectroscopy

The effect of Mg2+ on hepatic microsomal Ca2+ and Sr2+ transport

Beryllium, Lithium, Vanadium, Tungsten [Biomonitoring Methods, 1996]

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The characterization of primary, secondary, and tertiary vanadate alkyl esters by ⁵¹V nuclear magnetic resonance spectroscopy

The characterization of primary, secondary, and tertiary vanadate alkyl esters by ⁵¹V nuclear magnetic resonance spectroscopy