Studies of Electrode Reactions and Coordination Geometries of Cu(I) and Cu(II) Complexes with Bicinchoninic Acid

Studies of Electrode Reactions and Coordination Geometries of Cu(I) and Cu(II) Complexes with... Bicinchoninic acid (BCA) is widely used for determining the valence state of copper in biological systems and quantification of the total protein concentration (BCA assay). Despite its well‐known high selectivity of Cu(I) over Cu(II), the exact formation constants for Cu(I)(BCA)23− and Cu(II)(BCA)22− complexes remain uncertain. These uncertainties, affect the correct interpretations of the roles of copper in biological processes and the BCA assay data. By studying the voltammetric behaviors of Cu(I)(BCA)23− and Cu(II)(BCA)22−, we demonstrate that the apparent lack of redox reaction reversibility is caused by an adsorption wave of Cu(II)(BCA)22−. With the adsorption wave identified, we found that the Cu(I)/Cu(II) selectivity of BCA is essentially identical to another popular ligand, bathocuproinedisulfonic acid (BCS). Density functional theory calculation on the geometries of Cu(I)(BCA)23− and Cu(II)(BCA)22− rationalizes the preferential Cu(I) binding by BCA and the strong adsorption of the Cu(II)(BCA)22− complex at the glassy carbon electrode. Based on the shift in the standard reduction potential of free Cu(II)/Cu(I) upon binding to BCA, we affirm that the formation constants for Cu(I)(BCA)23− and Cu(II)(BCA)22− are 1017.2 and 108.9, respectively. Therefore, BCA can be chosen among various ligands for effective and reliable studies of the copper binding affinities of different biomolecules. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Electroanalysis Wiley

Studies of Electrode Reactions and Coordination Geometries of Cu(I) and Cu(II) Complexes with Bicinchoninic Acid

Loading next page...
 
/lp/wiley/studies-of-electrode-reactions-and-coordination-geometries-of-cu-i-and-AWmoGIdSN7
Publisher
Wiley Subscription Services, Inc., A Wiley Company
Copyright
© 2018 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim
ISSN
1040-0397
eISSN
1521-4109
D.O.I.
10.1002/elan.201700741
Publisher site
See Article on Publisher Site

Abstract

Bicinchoninic acid (BCA) is widely used for determining the valence state of copper in biological systems and quantification of the total protein concentration (BCA assay). Despite its well‐known high selectivity of Cu(I) over Cu(II), the exact formation constants for Cu(I)(BCA)23− and Cu(II)(BCA)22− complexes remain uncertain. These uncertainties, affect the correct interpretations of the roles of copper in biological processes and the BCA assay data. By studying the voltammetric behaviors of Cu(I)(BCA)23− and Cu(II)(BCA)22−, we demonstrate that the apparent lack of redox reaction reversibility is caused by an adsorption wave of Cu(II)(BCA)22−. With the adsorption wave identified, we found that the Cu(I)/Cu(II) selectivity of BCA is essentially identical to another popular ligand, bathocuproinedisulfonic acid (BCS). Density functional theory calculation on the geometries of Cu(I)(BCA)23− and Cu(II)(BCA)22− rationalizes the preferential Cu(I) binding by BCA and the strong adsorption of the Cu(II)(BCA)22− complex at the glassy carbon electrode. Based on the shift in the standard reduction potential of free Cu(II)/Cu(I) upon binding to BCA, we affirm that the formation constants for Cu(I)(BCA)23− and Cu(II)(BCA)22− are 1017.2 and 108.9, respectively. Therefore, BCA can be chosen among various ligands for effective and reliable studies of the copper binding affinities of different biomolecules.

Journal

ElectroanalysisWiley

Published: Jan 1, 2018

Keywords: ; ; ;

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

Monthly Plan

  • Read unlimited articles
  • Personalized recommendations
  • No expiration
  • Print 20 pages per month
  • 20% off on PDF purchases
  • Organize your research
  • Get updates on your journals and topic searches

$49/month

Start Free Trial

14-day Free Trial

Best Deal — 39% off

Annual Plan

  • All the features of the Professional Plan, but for 39% off!
  • Billed annually
  • No expiration
  • For the normal price of 10 articles elsewhere, you get one full year of unlimited access to articles.

$588

$360/year

billed annually
Start Free Trial

14-day Free Trial