In vitro induction and proteomics characterisation of a uranyl–protein interaction network in bovine serum

International audience; Uranyl ions (UO2 2+) were shown to interact with a number of foetal serum proteins, leading to the formation of a complex that could be isolated by ultracentrifugation. The molecular weight of the complex was estimated based on size-exclusion chromatography as 650 000 Da. Online ICP AES detection indicated that UO2 2+ in the complex co-eluted with minor amounts of calcium and phosphorous, but not with magnesium. A 1D gel electrophoresis of the U-complex produced more than 10 bands of similar intensity compared with only 2-3 intense bands corresponding to the main serum proteins in the control serum, indicative of the specific interaction of UO2 2+ with minor proteins. A proteomics approach allowed for the identification of 74 proteins in the complex. Analysis of the protein-protein interaction network in the UO2 2+ complex identified 32 proteins responsible for protein-protein complex formation and 34 with demonstrated ion-binding function, suggesting that UO2 2+ stimulates the formation of protein functional networks rather than using a particular molecule as its target. © 2015 The Royal Society of Chemistry.