Regensburg 2004 – scientific programme

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AKB: Biologische Physik

AKB 50: Poster Session "Biological Physics"

AKB 50.78: Poster

Friday, March 12, 2004, 10:30–13:00, B

ENZYME INDUCED STAINING OF BIOMEMBRANE WITH VOLTAGE SENSITIVE FLUORESCENT DYE — •Marlon Hinner, Gerd Hübener, and Peter Fromherz — Max-Planck-Institut für Biochemie, Dept. Membran- und Neurophysik, 82152 Martinsried

The application of fast voltage sensitive fluorescent dyes in brain is limited due to non-selective staining of the tissue. Here we describe a model experiment that may eventually lead to a selective staining of individual nerve cells by enzymatic activation of a water soluble dye precursor. Three steps were considered: (i) An amphiphilic hemicyanine dye with an alcohol headgroup and its phosphoric acid ester were synthesized. The partition coefficient of the phosphorylated dye between water and membrane is lower by a factor of about 16. (ii) The phosphorylated dye is converted to the corresponding alcohol by a phosphatase. (iii) Individual giant lipid vesicles and human erythrocytes are incubated with the phosporylated hemicyanine. Hydrolysis by added enzyme induces an increase of membrane fluorescence by a factor of 9 to 13 (vesicles) and 15-25 (erythrocytes). The model experiment forms the physicochemical basis for development of enzyme induced staining with genetically targeted cells.