title: Assembly and Calcium Binding Properties of Quantum Dot-Calmodulin Calcium Sensor.
abstract: We have developed the first nanoengineered quantum dot molecular complex designed to measure changes of calcium ion (Ca2+) concentration at high spatial and temporal resolutions in real time. The sensor is ratiometric and composed of three components: a quantum dot (QD) emitting at 620 nm as a fluorescence donor, an organic dye (Alexa Fluor 647) as a fluorescence acceptor, and a calmodulin-M13 (CaM-M13) protein part as a calcium sensing component. In this work, we have determined the maximal number of CaM-M13 required for saturating a single QD particle to be approximately 16. The dissociation constant, Kd of the QD-based calcium ion sensor was also estimated to be around 30 microM.
authors.forename: Su-yong
authors.initials: SY
authors.lastname: Eun
authors.forename: Kim
authors.initials: K
authors.lastname: Nguyen-ta
authors.forename: Hoon
authors.initials: H
authors.lastname: Yoo
authors.forename: Gabriel A
authors.initials: GA
authors.lastname: Silva
authors.forename: Soon-jong
authors.initials: SJ
authors.lastname: Kim