Stereospecificity of the metal.ATP complex in flavokinase from rat small intestine.

Nakano, Hikaru; McCormick, Donald B.

doi:10.1016/s0021-9258(18)54542-7

Cited by 20 publications

(9 citation statements)

References 22 publications

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“…ZnATP rather than MgATP is the preferred substrate for some kinases involved in cofactor biosynthesis: pyridoxal kinase, riboflavin kinase, and NAD kinase. − X-ray structures of the first two enzymes indeed show the interaction with a ZnATP complex. , Noteworthy, MT activates pyridoxal kinase . An equilibrium dialysis showed that ATP removes Zn(II) from MT.…”

Section: Relating Metallothionein Thermodynamics and Kinetics To Cont...mentioning

confidence: 99%

The Bioinorganic Chemistry of Mammalian Metallothioneins

2021

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The functions, purposes, and roles of metallothioneins have been the subject of speculations since the discovery of the protein over 60 years ago. This article guides through the history of investigations and resolves multiple contentions by providing new interpretations of the structure-stability-function relationship. It challenges the dogma that the biologically relevant structure of the mammalian proteins is only the one determined by X-ray diffraction and NMR spectroscopy. The terms metallothionein and thionein are ambiguous and insufficient to understand biological function. The proteins need to be seen in their biological context, which limits and defines the chemistry possible. They exist in multiple forms with different degrees of metalation and types of metal ions. The homoleptic thiolate coordination of mammalian metallothioneins is important for their molecular mechanism. It endows the proteins with redox activity and a specific pH dependence of their metal affinities. The proteins, therefore, also exist in different redox states of the sulfur donor ligands. Their coordination dynamics allows a vast conformational landscape for interactions with other proteins and ligands. Many fundamental signal transduction pathways regulate the expression of the dozen of human metallothionein genes. Recent advances in understanding the control of cellular zinc and copper homeostasis are the foundation for suggesting that mammalian metallothioneins provide a highly dynamic, regulated, and uniquely biological metal buffer to control the availability, fluctuations, and signaling transients of the most competitive Zn(II) and Cu(I) ions in cellular space and time.

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Section: Relating Metallothionein Thermodynamics and Kinetics To Cont...mentioning

confidence: 99%

The Bioinorganic Chemistry of Mammalian Metallothioneins

2021

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“…We have previously established the binding of ATP to MT by using an equilibrium method (3,14) and now employed other physical methods to determine structural details of the interaction between ATP and MT. We investigated whether 35 Cl NMR spectroscopy could be used to monitor the interaction between MT and ATP. Enhancement of chloride quadrupole relaxation by macromolecules has been employed as a probe for anion-binding sites of proteins (15), either on metal centers (16) or on protein side chains (17).…”

Section: Resultsmentioning

confidence: 99%

“…Enhancement of chloride quadrupole relaxation by macromolecules has been employed as a probe for anion-binding sites of proteins (15), either on metal centers (16) or on protein side chains (17). Addition of Cd 7 MT to a solution of 100 mM sodium chloride in buffer to yield a final concentration of 0.11 mM broadens the 35 Cl resonance from 15.1 Hz (Figure 1A) to 42.6 Hz (Figure 1B). These results identify chloride as an MT ligand.…”

Section: Resultsmentioning

confidence: 99%

“…With the goal of further characterizing the interactions between MT and ATP, we have extended structural aspects of this work by employing 35 Cl and 1 H NMR spectroscopy. As a consequence, we have identified chloride as an MT ligand and shown that binding of chloride competes with that of ATP.…”

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confidence: 99%

“…The mixing time was 80 ms, using a DIPSI-3 clean TOCSY mixing sequence with an RF field of 10 kHz. 35 Cl NMR Spectroscopy. Chloride NMR was performed on a Bruker 500 MHz spectrometer at 25 °C.…”

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The ATP/Metallothionein Interaction: NMR and STM

et al. 2002

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We have previously established that ATP binds to mammalian metallothionein-2 (MT). The interaction between ATP and MT and the associated conformational change of the protein affect the sulfhydryl reactivity and zinc transfer potential of MT [Jiang, L.-J., Maret, W., and Vallee, B. L. (1998) The ATP-metallothionein complex. Proc. Natl. Acad. Sci. U.S.A. 95, 9146-9149]. NMR spectroscopic investigations have now provided further evidence for the interaction. (35)Cl NMR spectroscopy has further identified chloride as an additional biological MT ligand, which can interfere with the interaction of ATP with MT. (1)H NMR/TOCSY spectra demonstrate that ATP binding affects the N- and C-terminal amino acids of the MT molecule. Scanning tunneling microscopy recorded images of single MT molecules in buffered solutions. Moreover, this technique demonstrates that the otherwise nearly linear MT molecule bends by about 20 degrees at its central hinge region between the domains in the presence of ATP. These results may bear on the development of mild obesity in MT null mice and the role of MT in the regulation of energy balance. The interaction suggests a mechanism for the cellular translocation, retention, and reactivity of the ATP*MT complex in the mitochondrial intermembrane space. Both MT and ATP are localized there, and MT and thionein alternately bind and release zinc, thereby affecting mitochondrial respiration.

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Zinc status in autistic children

Yorbık

Akay²,

Sayal³

et al. 2004

J Trace Elements Exper Med

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The transition metal zinc is an essential element for normal development and function of biological systems including the central nervous system (CNS). Zinc may be an important trace element for the etiology and symptoms of subgroups of autistic children because it is an essential catalytic or structural element of many proteins and important for neural activity and the control of neuronal death. The aim of this study was to evaluate zinc status in children with autistic disorder. Plasma, erythrocyte, and hair zinc levels were measured by atomic absorption spectrophotometry in the 45 and 39 autistic children, respectively. Forty-one healthy children 3 in the same age group were selected as controls. Plasma and erythrocyte zinc levels in the autistic children were found to be significantly lower than normal (P < 0.05). The mean hair zinc level of the patients was also low when compared with that obtained from normal Turkish children. These results may indicate chronic zinc deficiency or metabolic abnormality of zinc in autistic children. Further studies are required to clarify underlying mechanisms.

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Stereospecificity of the metal.ATP complex in flavokinase from rat small intestine.

Cited by 20 publications

References 22 publications

The Bioinorganic Chemistry of Mammalian Metallothioneins

The Bioinorganic Chemistry of Mammalian Metallothioneins

The ATP/Metallothionein Interaction: NMR and STM

Zinc status in autistic children

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