Cu(CH3CN) 2 + , ein Mittel zum Studium homogener Reaktionen des einwertigen Kupfers in wässriger Lösung

Hemmerich, P.; Sigwart, Christoph

doi:10.1007/bf02150666

Cited by 224 publications

(86 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Miscellaneous Methods-The synthesis of diacetonitrilo-copper(I) perchlorate, [Cu(I)(CH 3 CN) 2 ]ClO 4 , was performed as described (34). Protein concentrations were determined by quantitative amino acid analysis, and copper concentrations were determined by flame atomic absorption spectroscopy, using a Varian A-8875 instrument.…”

Section: Methodsmentioning

confidence: 99%

NMR Structure and Metal Interactions of the CopZ Copper Chaperone

Wimmer¹,

Herrmann²,

Solioz

et al. 1999

Journal of Biological Chemistry

120

136

View full text Add to dashboard Cite

A recently discovered family of proteins that function as copper chaperones route copper to proteins that either require it for their function or are involved in its transport. In Enterococcus hirae the copper chaperone function is performed by the 8-kDa protein CopZ. This paper describes the NMR structure of apo-CopZ, obtained using uniformly 15 N-labeled CopZ overexpressed in Escherichia coli and NMR studies of the impact of Cu(I) binding on the CopZ structure. The protein has a ␤␣␤␤␣␤ fold, where the four ␤-strands form an antiparallel twisted ␤-sheet, and the two helices are located on the same side of the ␤-sheet. A sequence motif GMX-CXXC in the loop between the first ␤-strand and the first ␣-helix contains the primary ligands, which bind copper(I). Binding of copper(I) caused major structural changes in this molecular region, as manifested by the fact that most NMR signals of the loop and the N-terminal part of the first helix were broadened beyond detection. This effect was strictly localized, because the remainder of the apo-CopZ structure was maintained after addition of Cu(I). NMR relaxation data showed a decreased correlation time of overall molecular tumbling for Cu(I)-CopZ when compared with apo-CopZ, indicating aggregation of Cu(I)-CopZ. The structure of CopZ is the first three-dimensional structure of a cupro-protein for which the metal ion is an exchangeable substrate rather than an integral part of the structure. Implications of the present structural work for the in vivo function of CopZ are discussed, whereby it is of special interest that the distribution of charged residues on the CopZ surface is highly uneven and suggests preferred recognition sites for other proteins that might be involved in copper transfer.

show abstract

Section: Methodsmentioning

confidence: 99%

NMR Structure and Metal Interactions of the CopZ Copper Chaperone

Wimmer¹,

Herrmann²,

Solioz

et al. 1999

Journal of Biological Chemistry

120

136

View full text Add to dashboard Cite

show abstract

“…Diphenylthiocarbazone and o-nitrophenyl-␤-D-galactopyranoside were purchased from Sigma, and bathocuproine disulfonic acid was purchased from Aldrich. The Cu(I)-acetonitrile complex (Cu I (CH 3 CN) 2 ClO 4 ) was synthesized according to the method of Hemmerich and Sigwart (18). All other chemicals and solutions were purchased from commercial suppliers and were of the highest purity available.…”

Section: Methodsmentioning

confidence: 99%

The interaction of nitric oxide (NO) with the yeast transcription factor Ace1: A model system for NO-protein thiol interactions with implications to metal metabolism

Shinyashiki

Chiang

Switzer

et al. 2000

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Nitric oxide (NO) was found to inhibit the copper-dependent induction of the yeast CUP1 gene. This effect is attributable to an inhibition of the copper-responsive CUP1 transcriptional activator Ace1. A mechanism is proposed whereby the metal binding thiols of Ace1 are chemically modified via NO-and O 2-dependent chemistry, thereby diminishing the ability of Ace1 to bind and respond to copper. Moreover, it is proposed that demetallated Ace1 is proteolytically degraded in the cell, resulting in a prolonged inhibition of copper-dependent CUP1 induction. These findings indicate that NO may serve as a disrupter of yeast copper metabolism. More importantly, considering the similarity of Ace1 to other mammalian metal-binding proteins, this work lends support to the hypothesis that NO may regulate͞disrupt metal homeostasis under both normal physiological and pathophysiological circumstances. For example, NO generated by vascular endothelial cells is a messenger molecule involved in the maintenance of vascular tone via interaction with the heme enzyme guanylate cyclase (2). Nitric oxide is also involved in central nervous system function, where it serves as an activator of guanylate cyclase (3). Thus, in its role as a mediator of vascular tone and as a signal transduction agent in the central nervous system, NO appears to act primarily by activating guanylate cyclase, leading to increased levels of the cellular messenger cGMP. However, NO generated from activated macrophages during an immune response is thought to have cytotoxic and͞or cytostatic properties against target organisms in a largely cGMP-independent fashion (4). One important cGMP-independent function of NO is as a regulator of cellular iron metabolism (5), as NO has been found to alter the activity of iron regulatory protein, an important protein involved in the maintenance in iron homeostasis (6). It is likely that alterations in metal metabolism elicited by NO may represent an important aspect of its pathophysiology.It appears that one important aspect of NO physiology and pathophysiology involves its interactions with protein thiols. That is, the activation and inactivation of thiol-containing proteins by NO are thought to be responsible for some of the biological actions of NO (for reviews, see refs. 7-9). Recent and profound discoveries in the yeast Saccharomyces cerevisiae indicate that the intracellular transport, sequestration, and uptake of metals occurs through the actions of many thiol-containing proteins. For example, the yeast copper chaperones Lys7, Atx1, Cox17, and Ccc2 all appear to bind copper via thiol ligation (ref. 10 and references therein). Also, the yeast metallothioneins sequester ''free'' copper by using thiol-rich metal binding domains (11). Finally, the yeast metal-responsive transcription factors Ace1 and Mac1 are responsible for the expression of a variety of metal regulatory proteins and appear to respond to copper by binding it in an analogous fashion to metallothionein (12-16). Considering the known chemical and biochemical i...

show abstract

“…Highly e⁄cient chelators of copper(I) in vitro are o-phenanthroline, bathophenanthroline sulfonate or 8-hydroxyquinoline (reported formation constants for copper^phenanthroline complexes are around 21, irrespective of the ligands on the phenanthroline dipyrimidine ring system [3]). Stable copper(I) complexes are also formed by acetonitrile [4], CN 3 , or even Tris-bu¡er [5]. More recently, tetrathiomolybdate has been employed as a very potent copper chelator in experimental systems [6].…”

Section: The Chemical State Of Coppermentioning

confidence: 99%

Copper homeostasis inEnterococcus hirae

2003

View full text Add to dashboard Cite

Copper is an essential component of life because of its convenient redox potential of 200^800 mV when bound to protein. Extensive insight into copper homeostasis has only emerged in the last decade and Enterococcus hirae has served as a paradigm for many aspects of the process. The cop operon of E. hirae regulates copper uptake, availability, and export. It consists of four genes that encode a repressor, CopY, a copper chaperone, CopZ, and two CPx-type copper ATPases, CopA and CopB. Most of these components have been conserved across the three evolutionary kingdoms. The four Cop proteins have been studied in vivo as well as in vitro and their function is understood in some detail.

show abstract

Cu(CH3CN) 2 + , ein Mittel zum Studium homogener Reaktionen des einwertigen Kupfers in wässriger Lösung

Cited by 224 publications

References 1 publication

NMR Structure and Metal Interactions of the CopZ Copper Chaperone

NMR Structure and Metal Interactions of the CopZ Copper Chaperone

The interaction of nitric oxide (NO) with the yeast transcription factor Ace1: A model system for NO-protein thiol interactions with implications to metal metabolism

Copper homeostasis inEnterococcus hirae

Contact Info

Product

Resources

About