Jump to main content
Jump to site search
PLANNED MAINTENANCE Close the message box

Scheduled maintenance work on Wednesday 22nd May 2019 from 11:00 AM to 1:00 PM (GMT).

During this time our website performance may be temporarily affected. We apologise for any inconvenience this might cause and thank you for your patience.

Issue 11, 2001
Previous Article Next Article

Determination of the complex stability of zinc with carbonic anhydrase in sea-water

Author affiliations


Carbonic anhydrase (CA) is inactive unless associated with zinc, with possible substitution by cobalt. In this work, the complexation of zinc by CA was determined in sea-water using cathodic stripping voltammetry (CSV) with ligand competition. The zinc was found to be released from the CA over a period of 3 h when equilibrated with a competing complexing ligand and the complex was re-formed with the CA when zinc was added. A value of 8.90 ± 0.27 was found for logKZnCA where KZnCA is the conditional stability constant for the complex of Zn2+ with CA in pH 8 sea-water. A value for the molecular weight of CA was calculated from its equivalent ligand concentration (in nM) obtained by titrations with zinc at various CA concentrations (1–4 mg l−1). The value found (34740 g mol−1) for the molecular weight is consistent with values found previously by other methods (29000–31000 g mol−1) confirming that the stoichiometry of the complex between zinc and CA is 1∶1. This work confirms that the zinc–CA complex is reversible and that the interaction between zinc and CA can be determined using CSV with ligand competition.

Back to tab navigation

Publication details

The article was received on 19 Jun 2001, accepted on 20 Aug 2001 and first published on 10 Oct 2001

Article type: Paper
DOI: 10.1039/B105364G
Analyst, 2001,126, 2036-2039

  •   Request permissions

    Determination of the complex stability of zinc with carbonic anhydrase in sea-water

    G. Sarthou, C. M. G. van den Berg and U. Riebesell, Analyst, 2001, 126, 2036
    DOI: 10.1039/B105364G

Search articles by author