Figure 4. Characterization of QD-BBS protein conjugates.

(A) Electrophoretic mobility of QDs and QD-conjugates in 1% agarose gel, in Tris-acetate-EDTA buffer (pH 7.4). QDs run from cathode (–) to anode (+). Lanes: 1 – QD₆₀₅, 2 – mixture of QD₆₀₅ and barstar (without EDC), 3 - QD₆₀₅-Bs conjugate, 4- QD₅₆₅, 5 –mixture of QD₅₆₅ and barnase (without EDC), 6 - QD₅₆₅-Bn conjugate. (B) Normalized fluorescence spectra of QD₅₆₅ (blue line), QD₆₀₅ (violet line) and their conjugates, QD₅₆₅-Bn (green line) and QD₆₀₅-Bs (red line). (C) The ribonuclease activity of QD₆₀₅-Bn (red line and circles) and free barnase RNAse activity inhibition of QD₆₀₅-Bs (blue line and square). QD₆₀₅ (green line) do not affect ribonuclease activity of barnase.