In situ Measurement of Free Zinc in an Ischemia Model and Cell Culture Using a Ratiometric Fluorescence-Based Biosensor

摘要

Zinc ion is of growing interest in medicine and biology generally, and especially in the ischemic brain and other tissues. We have developed ratiometric fluorescence-based biosensors for the study of zinc in these systems; the biosensors use apocarbonic anhydrase variants as recognition elements that offer high sensitivity and selectivity. We report continuous in situ, in vivo measurement of nanomolar extracellular zinc in the brain of an animal model of ischemia using a ratiometric fiber optic biosensor. We also report the development of an expressible excitation ratiometric indicator of zinc ion suitable for use in cells that exhibits picomolar sensitivity. Finally, we also report the discovery that the Zn complex of the chelator TPEN seems to be comparably apoptogenic to the free chelator itself.