✦ LIBER ✦

Studies of Zn(II) and Co(II) complexes of imidazole and N-methylimidazole with regard to the activity related ionization in carbonic anhydrase

✍ Scribed by David W. Appleton; Bibudhendra Sarkar

Publisher: Elsevier Science
Year: 1977
Weight: 876 KB
Volume: 7
Category: Article
ISSN: 0006-3061
DOI: 10.1016/s0006-3061(00)80095-2

No coin nor oath required. For personal study only.

✦ Synopsis

Mixed aquo-N-methylimidazole complexes of Co(II) have been studied as a function of pH to gain a fuller understanding of the metal-binding site in Co(II)-carbonic anhydrase. The inherent affinity of N-methylimidazole for Co(II) has been calculated along with a species distribution for the stepwise addition of ligand to the metal ion. From these studies, it is apparent that the occurrence of Zn(II) rather than Co(II) in native carbonic anhydrase can be explained by the stronger affinity of Zn(II) for imidazole and the preference of Zn(II) for a tetrahedral geometry as offered by the enzyme. Octahedral Co(II) fails to ionize metal bound water. However, at high pH, Co(II)-N-methylimidazole complexes interact directly with the hydroxide ion, generating species with visible spectra very similar to that of Co(II)-carbonic anhydrase. Tentative structures have been proposed for these species.

📜 SIMILAR VOLUMES

Mechanistic information on the reaction

Mechanistic information on the reaction of model palladium(II) complexes with purine nucleosides and 5′-nucleotides in reference to the antitumor activity of related platinum complexes

✍ M. Shoukry; H. Hohmann; R. van Eldik 📂 Article 📅 1992 🏛 Elsevier Science 🌐 English ⚖ 572 KB

The reaction of Pd(Me,en)Cl, (Me,en =N,N,iV',N'-tetramethylethylenediamine) with inosine and 5'-inosine monophosphate was studied as a function of chloride concentration and pH. Evidence for the formation of a 1:l complex with these nucleophiles is presented, and the kinetic data indicate that Pd(Me