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Updated: May 22, 2026

Conjugative Mating Assays for Sequence-specific Analysis of Transfer Proteins Involved in Bacterial Conjugation
Published on: January 4, 2017
Looking for the origin of the switch between coordination-captured helicates and catenates
Lilit Aboshyan-Sorgho1, Martine Cantuel, Gérald Bernardinelli
1Department of Inorganic and Analytical Chemistry, University of Geneva, 30 quai E. Ansermet, CH-1211 Geneva 4, Switzerland.
Abstract:
Self-assembly of the linear segmental ligand L5, consisting of a tridentate binding unit flanked with two bidentate binding units, with a mixture of Fe(II)/Ag(I) yields the trinuclear coordination-captured [2]catenate [AgFeAg(L5)(2)](4+) instead of the planned isomeric double-stranded helicate. Replacing the octahedral (Fe(II)) and tetrahedral (Ag(I)) cations with Zn(II), which is compatible with both geometries, gives intricate mixtures of homometallic complexes upon reaction with the twin ligand L6, from which the macrocyclic dinuclear complex [Zn(2)(L6)](4+) can be isolated. Application of the thermodynamic site binding model attributes the origin of the ligand preference for producing single-stranded macrocycles, the precursors of the trinuclear catenate, to the abnormally low value of the effective molarity controlling the intramolecular connection leading to the usual double-stranded helical isomer.
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