A1 Refereed original research article in a scientific journal
Cd2+-induced aggregation of Escherichia coli pyrophosphatase
Authors: Zimenkov YV, Salminen A, Efimova IS, Lahti R, Baykov AA
Publisher: BLACKWELL PUBLISHING LTD
Publication year: 2004
Journal: European Journal of Biochemistry
Journal name in source: EUROPEAN JOURNAL OF BIOCHEMISTRY
Journal acronym: EUR J BIOCHEM
Volume: 271
Issue: 14
First page : 3064
Last page: 3067
Number of pages: 4
ISSN: 0014-2956
DOI: https://doi.org/10.1111/j.1432-1033.2004.04239.x(external)
Abstract
We report here that Escherichia coli pyrophosphatase aggregates in the presence of millimolar Cd2+. This highly cooperative process was specific to both the metal ion and the protein and could be reversed fully by decreasing the Cd2+ concentration. Aggregation was enhanced by Mg2+, the natural cofactor of pyrophosphatase, and Mn2+. Mutations at the intersubunit metal-binding site had no effect, whereas mutation at Glu139, which is part of the peripheral metal-binding site found in pyrophosphatase crystals near the contact region between two enzyme molecules, suppressed aggregation. These findings indicate that aggregation is affected by Cd2+ binding to the peripheral metal-binding site, probably by strengthening intermolecular Trp149-Trp149' stacking interactions.
We report here that Escherichia coli pyrophosphatase aggregates in the presence of millimolar Cd2+. This highly cooperative process was specific to both the metal ion and the protein and could be reversed fully by decreasing the Cd2+ concentration. Aggregation was enhanced by Mg2+, the natural cofactor of pyrophosphatase, and Mn2+. Mutations at the intersubunit metal-binding site had no effect, whereas mutation at Glu139, which is part of the peripheral metal-binding site found in pyrophosphatase crystals near the contact region between two enzyme molecules, suppressed aggregation. These findings indicate that aggregation is affected by Cd2+ binding to the peripheral metal-binding site, probably by strengthening intermolecular Trp149-Trp149' stacking interactions.