An Arsenic Fluorescent Compound as a Novel Probe to Study Arsenic-Binding Proteins

作者：Lis Femia A; Facundo Temprana C; Santos Javier; Laura Carbajal Maria; Silvia Amor Maria; Grasselli Mariano; Alonso Silvia del V^*

来源：Protein Journal, 2012, 31(8): 656-666.

DOI：10.1007/s10930-012-9441-6

• Arsenic carcinogenesis
• Circular dichroism
• Conformational studies
• Drug delivery systems
• Thioredoxin

Arsenic-binding proteins are under continuous research. Their identification and the elucidation of arsenic/protein interaction mechanisms are important because the biological effects of these complexes may be related not only to arsenic but also to the arsenic/protein structure. Although many proteins bearing a CXXC motif have been found to bind arsenic in vivo, new tools are necessary to identify new arsenic targets and allow research on protein/arsenic complexes. In this work, we analyzed the performance of the fluorescent compound APAO-FITC (synthesized from p-aminophenylarsenoxide, APAO, and fluorescein isothiocyanate, FITC) in arsenic/protein binding assays using thioredoxin 1 (Trx) as an arsenic-binding protein model. The Trx-APAO-FITC complex was studied through different spectroscopic techniques involving UV-Vis, fluorescence, atomic absorption, infrared and circular dichroism. Our results show that APAO-FITC binds efficiently and specifically to the Trx binding site, labeling the protein fluorescently, without altering its structure and activity. In summary, we were able to study a protein/arsenic complex model, using APAO-FITC as a labeling probe. The use of APAO-FITC in the identification of different protein and cell targets, as well as in in vivo biodistribution studies, conformational studies of arsenic-binding proteins, and studies for the design of drug delivery systems for arsenic anti-cancer therapies, is highly promising.

• 出版日期2012-12