scholarly journals Copper-mediated dimerization of CopZ, a predicted copper chaperone from Bacillus subtilis

2002 ◽  
Vol 368 (3) ◽  
pp. 729-739 ◽  
Author(s):  
Margaret A. KIHLKEN ◽  
Andrew P. LEECH ◽  
Nick E. LE BRUN
Keyword(s):  
Bacillus Subtilis ◽  
Metal Binding ◽  
Metal Ion ◽  
Complex Nature ◽  
Binding Motif ◽  
Copper Chaperone ◽  
Ion Transfer ◽  
Copper Binding ◽  
Binding Properties ◽  
In The Wild

Understanding the metal-binding properties and solution states of metallo-chaperones is a key step in understanding how they function in metal ion transfer. Using spectroscopic, bioanalytical and biochemical methods, we have investigated the copper-binding properties and association states of the putative copper chaperone of Bacillus subtilis, CopZ, and a variant of the protein lacking the two cysteine residues of the MXCXXC copper-binding motif. We show that copper-free CopZ exists as a monomer, but that addition of copper(I) causes the protein to associate into homodimers. The nature of the copper(I)—CopZ complex is dependent on the level of copper loading, and we report the detection of three distinct forms, containing 0.5, 1.0 and 1.5 copper(I) ions per protein. The presence of excess dithiothreitol has a significant effect on copper(I) binding to CopZ, such that, in its presence, copper(I)—CopZ occurs mainly as a monomer species. Data for copper binding to the double-cysteine variant of CopZ are consistent with an essential role for these residues in tight copper binding in the wild-type protein. We conclude that the complex nature of copper(I) binding to CopZ may underpin mechanisms of protein-to-protein copper(I) transfer.

Copper chaperone Atox1 interacts with the metal-binding domain of Wilson's disease protein in cisplatin detoxification

2013 ◽  
Vol 454 (1) ◽  
pp. 147-156 ◽  
Author(s):  
Nataliya V. Dolgova ◽  
Sergiy Nokhrin ◽  
Corey H. Yu ◽  
Graham N. George ◽  
Oleg Y. Dmitriev
Keyword(s):  
Metal Binding ◽  
Wilson’S Disease ◽  
Wilson's Disease ◽  
Binding Domain ◽  
Binding Motif ◽  
Copper Chaperone ◽  
Copper Binding ◽  
Copper Transporters ◽  
Metal Binding Domain ◽  
Disease Protein

Human copper transporters ATP7B (Wilson's disease protein) and ATP7A (Menkes' disease protein) have been implicated in tumour resistance to cisplatin, a widely used anticancer drug. Cisplatin binds to the copper-binding sites in the N-terminal domain of ATP7B, and this binding may be an essential step of cisplatin detoxification involving copper ATPases. In the present study, we demonstrate that cisplatin and a related platinum drug carboplatin produce the same adduct following reaction with MBD2 [metal-binding domain (repeat) 2], where platinum is bound to the side chains of the cysteine residues in the CxxC copper-binding motif. This suggests the same mechanism for detoxification of both drugs by ATP7B. Platinum can also be transferred to MBD2 from copper chaperone Atox1, which was shown previously to bind cisplatin. Binding of the free cisplatin and reaction with the cisplatin-loaded Atox1 produce the same protein-bound platinum intermediate. Transfer of platinum along the copper-transport pathways in the cell may serve as a mechanism of drug delivery to its target in the cell nucleus, and explain tumour-cell resistance to cisplatin associated with the overexpression of copper transporters ATP7B and ATP7A.

scholarly journals Metal ion recognition of the metal-binding motif in hammerhead ribozymes

2003 ◽  
Vol 43 (supplement) ◽  
pp. S28
Author(s):  
Y. Tanaka ◽  
Y. Kasai ◽  
C. Kojima ◽  
K. Yamasaki ◽  
H. Morita ◽  
...  
Keyword(s):  
Metal Binding ◽  
Metal Ion ◽  
Binding Motif ◽  
Hammerhead Ribozymes ◽  
Ion Recognition ◽  
Metal Binding Motif

High Cu(I) and low proton affinities of the CXXC motif of Bacillus subtilis CopZ

2008 ◽  
Vol 413 (3) ◽  
pp. 459-465 ◽  
Author(s):  
Liang Zhou ◽  
Chloe Singleton ◽  
Nick E. Le Brun
Keyword(s):  
Bacillus Subtilis ◽  
Ph Dependence ◽  
Binding Motif ◽  
Copper Chaperone ◽  
Proton Affinities ◽  
Copper Trafficking ◽  
Cellular Machinery ◽  
Bacterium Bacillus Subtilis ◽  
Bacterium Bacillus ◽  
Simple Dissociation

CopZ, an Atx1-like copper chaperone from the bacterium Bacillus subtilis, functions as part of a complex cellular machinery for Cu(I) trafficking and detoxification, in which it interacts specifically with the transmembrane Cu(I)-transporter CopA. Here we demonstrate that the cysteine residues of the MXCXXC Cu(I)-binding motif of CopZ have low proton affinities, with both exhibiting pKa values of 6 or below. Chelator competition experiments demonstrated that the protein binds Cu(I) with extremely high affinity, with a small but significant pH-dependence over the range pH 6.5–8.0. From these data, a pH-corrected formation constant, β2=∼6×1022 M−2, was determined. Rapid exchange of Cu(I) between CopZ and the Cu(I)-chelator BCS (bathocuproine disulfonate) indicated that the mechanism of exchange does not involve simple dissociation of Cu(I) from CopZ (or BCS), but instead proceeds via the formation of a transient Cu(I)-mediated protein–chelator complex. Such a mechanism has similarities to the Cu(I)-exchange pathway that occurs between components of copper-trafficking pathways.

scholarly journals Unravelling the Structure of the Tetrahedral Metal-Binding Site in METP3 through an Experimental and Computational Approach

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5221
Author(s):  
Salvatore La Gatta ◽  
Linda Leone ◽  
Ornella Maglio ◽  
Maria De Fenza ◽  
Flavia Nastri ◽  
...  
Keyword(s):  
Metal Ions ◽  
Binding Site ◽  
Metal Binding ◽  
Binding Sites ◽  
Metal Ion ◽  
Structural Determinants ◽  
Binding Properties ◽  
Tetrahedral Geometry ◽  
Design Synthesis ◽  
Metal Binding Sites

Understanding the structural determinants for metal ion coordination in metalloproteins is a fundamental issue for designing metal binding sites with predetermined geometry and activity. In order to achieve this, we report in this paper the design, synthesis and metal binding properties of METP3, a homodimer made up of a small peptide, which self assembles in the presence of tetrahedrally coordinating metal ions. METP3 was obtained through a redesign approach, starting from the previously developed METP molecule. The undecapeptide sequence of METP, which dimerizes to house a Cys4 tetrahedral binding site, was redesigned in order to accommodate a Cys2His2 site. The binding properties of METP3 were determined toward different metal ions. Successful assembly of METP3 with Co(II), Zn(II) and Cd(II), in the expected 2:1 stoichiometry and tetrahedral geometry was proven by UV-visible spectroscopy. CD measurements on both the free and metal-bound forms revealed that the metal coordination drives the peptide chain to fold into a turned conformation. Finally, NMR data of the Zn(II)-METP3 complex, together with a retrostructural analysis of the Cys-X-X-His motif in metalloproteins, allowed us to define the model structure. All the results establish the suitability of the short METP sequence for accommodating tetrahedral metal binding sites, regardless of the first coordination ligands.

Spectroscopic, computational and molecular docking study of Cu(II) complexes with flavonoids: From cupric ion binding to DNA intercalation.

2021 ◽  
Author(s):  
Miriama Šimunková ◽  
Marek Štekláč ◽  
Michal Malček
Keyword(s):  
Oxidative Stress ◽  
Metal Binding ◽  
Metal Ion ◽  
Docking Study ◽  
Polyphenolic Compounds ◽  
Dna Intercalation ◽  
Ion Binding ◽  
Molecular Docking Study ◽  
Binding Properties ◽  
Cupric Ion

Polyphenolic compounds such as flavonoids are closely linked with therapeutical approaches in oxidative stress related diseases mainly because of their antioxidant and metal binding properties. The formation of metal ion...

Cobalt(2+) Binding to Human and Tomato Copper Chaperone for Superoxide Dismutase:  Implications for the Metal Ion Transfer Mechanism†,‡

Biochemistry ◽  
2000 ◽  
Vol 39 (18) ◽  
pp. 5413-5421 ◽  
Author(s):  
Haining Zhu ◽  
Eric Shipp ◽  
Raylene J. Sanchez ◽  
Amir Liba ◽  
Jennifer E. Stine ◽  
...  
Keyword(s):  
Superoxide Dismutase ◽  
Metal Ion ◽  
Transfer Mechanism ◽  
Copper Chaperone ◽  
Ion Transfer

scholarly journals Role of the HPRG Component of Striated Muscle AMP Deaminase in the Stability and Cellular Behaviour of the Enzyme

Biomolecules ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 79
Author(s):  
Francesca Ronca ◽  
Antonio Raggi
Keyword(s):  
Metal Binding ◽  
Thin Filament ◽  
Striated Muscle ◽  
Binding Motif ◽  
Amp Deaminase ◽  
Binding Properties ◽  
Preferential Localization ◽  
The Stability ◽  
Cellular Behaviour

Multiple muscle-specific isoforms of the Zn2+ metalloenzyme AMP deaminase (AMPD) have been identified based on their biochemical and genetic differences. Our previous observations suggested that the metal binding protein histidine-proline-rich glycoprotein (HPRG) participates in the assembly and maintenance of skeletal muscle AMP deaminase (AMPD1) by acting as a zinc chaperone. The evidence of a role of millimolar-strength phosphate in stabilizing the AMPD-HPRG complex of both AMPD1 and cardiac AMP deaminase (AMPD3) is suggestive of a physiological mutual dependence between the two subunit components with regard to the stability of the two isoforms of striated muscle AMPD. The observed influence of the HPRG content on the catalytic behavior of the two enzymes further strengthens this hypothesis. Based on the preferential localization of HPRG at the sarcomeric I-band and on the presence of a Zn2+ binding motif in the N-terminal regions of fast TnT and of the AMPD1 catalytic subunit, we advance the hypothesis that the Zn binding properties of HPRG could promote the association of AMPD1 to the thin filament.

Metal Ion Binding Properties of Perfluorosulfonate Membranes by Laser Excitation Spectroscopy

1988 ◽  
Vol 42 (2) ◽  
pp. 293-295 ◽  
Author(s):  
E. K. L. Wong ◽  
G. L. Richmond
Keyword(s):  
Metal Binding ◽  
Binding Sites ◽  
Metal Ion ◽  
Laser Excitation ◽  
Ion Binding ◽  
Metal Ion Binding ◽  
Binding Properties ◽  
Metal Binding Sites ◽  
Fluorescence Measurements ◽  
Experimental Parameters

The metal ion binding properties of the perfluorosulfonate membrane Nafion® have been investigated in this study. The experiments involve laser-induced fluorescence measurements of europium (III) ions which are bound to the membrane. By the exploitation of the hypersensitivity of the D → F transitions of europium (III) to the ligand binding environment, the properties of the metal binding sites have been analyzed as a function of various experimental parameters. The spectra and fluorescence lifetime measurements provide evidence for distinct metal binding sites within the polymer, each of which is sensitive to the conditions of the membrane preparation.

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