1 May 1998 Mag-indo-1 as a potential reporter of the 3D conformation of protein subdomains
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Proceedings Volume 3253, Biomedical Sensing and Imaging Technologies; (1998) https://doi.org/10.1117/12.308035
Event: BiOS '98 International Biomedical Optics Symposium, 1998, San Jose, CA, United States
Mag-indo-1 is a well known fluorescent probe. Magnesium complexation results in a shift of the emission fluorescence spectrum from 480 nm to 417 nm with an intensity proportional to the magnesium concentration in the range 0.6 to 30 mM. Although designed as a specific magnesium chelator, Mag-indo-1 is also able to bind calcium and zinc. All these cationic interactions induced the same spectral shift but the fluorescence intensity and the dissociation constant are dependent of the nature of the cation. Furthermore Mag-indo-1 can also bind proteins through a specific interaction with some histidin residues. That interaction induces a characteristic spectral shift of the emission fluorescence spectra from 480 to 457 nM. All these properties suggest that Mag-indo-1 could be used to study the protein-cation binding. Emission and synchronous fluorescence techniques have been used to monitor that interaction with proteins such as bovine serum albumin, human serum albumin, turkey white egg lysozyme. Using a method of resolution of complex fluorescence spectra, it has been possible to calculate the number of interaction sites and the correlative dissociation constants. Depending on the nature of the protein a quenching of the natural fluorescence of the protein was observed, associated with an energy transfer from some tryptophan(s) to Mag-indo-1. All these data were tentatively correlated with the available information on the 3D conformation of the proteins. These results suggest that Mag-indo-1 could be used as an intramolecular fluorescent ruler to monitor the changes in 3D conformation of specific sub-domains of proteins.
© (1998) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Pierre M. Viallet, Pierre M. Viallet, Tuan Vo-Dinh, Tuan Vo-Dinh, Terry Bunde, Terry Bunde, Anne-Cecile Ribou, Anne-Cecile Ribou, Jean Vigo, Jean Vigo, Jean-Marie Salmon, Jean-Marie Salmon, } "Mag-indo-1 as a potential reporter of the 3D conformation of protein subdomains", Proc. SPIE 3253, Biomedical Sensing and Imaging Technologies, (1 May 1998); doi: 10.1117/12.308035; https://doi.org/10.1117/12.308035


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