Addition/Correction pubs.acs.org/JPCB
Correction to “Multidonor Deep-UV FRET Study of Protein−Ligand Binding and Its Potential to Obtain Structure Information” Qiang Li, Dorinel Verdes, and Stefan Seeger* J. Phys. Chem. B 2011, 115 (46), 13643−13649. DOI: 10.1021/jp2035289 × 10−15 M). Most of the biotinylated βGAL and avidin-AF350 form complexes under the experimental conditions; the free biotinylated βGAL and avidin-AF350 fractions are quite low compared with the complex. We also performed a control experiment by coating biotinylated βGAL or avidin-AF350 on quartz coverslips using 1 × 10−6 mol/L solution; the contribution of fluorescence intensity at 430−470 nm is less than 10% compared with that in Figure 5. Therefore, the fluorescence signal of free donor and acceptor is negligible, also because the concentration of free donor and acceptor is tremendously lower after the binding reaction. The fluorescence image from AF350 emission in Figure 5 indicates a FRET process from βGAL to AF350 after the biotin−avidin binding reaction. The average fluorescence lifetime of biotinylated βGAL decreases due to binding with avidin-AF350. This change of the average lifetime of donor fluorescence is used to quantify the sensitivity of our method for UV FRET based on biotin− AF350 binding reaction. Figure 6 shows the average fluorescence lifetime changes between free biotinylated βGAL and avidin-AF350 bound biotinylated βGAL measured by keeping the molar ratio of biotinylated βGAL and avidin-AF350 at 1:3 and varying the biotinylated βGAL concentration. We did not observe a significant average fluorescence lifetime change at biotinylated βGAL concentrations less than 5 × 10−10 mol/L. We observe the average fluorescence lifetime changes at biotinylated βGAL concentrations from 1 × 10−9 mol/L and higher concentrations. The changes remain at a constant level at donor concentrations between 5 × 10−9 and 1 × 10−6 mol/L. Figure 5 was also used in the Table of Contents (TOC) image. The revised TOC graphic is shown below.
I
n the Results and Discussion section of this paper, we show the fluorescence intensity image of AF350 on the quartz surface after UV FRET based on a biotin−avidin binding reaction (Figure 5). Unfortunately, the published Figures 5 and 6 do not represent the results appropriately. The correct figures are shown below.
Figure 5. Image of AF350 on a quartz surface after UV FRET based on biotin−avidin binding reaction. The image was measured using deep UV fluorescence imaging microscopy at a detection window of 430−470 nm.
1 × 10−6 mol/L biotinylated βGAL and avidin-AF350 mixture solution (ratio 1:3) was adsorbed on quartz coverslips by spin coating. The fluorescence signal on the quartz surface has been observed at 430−470 nm after excitation at 266 nm using deep UV fluorescence imaging microscopy. The binding constant of biotin and avidin interaction is quite large (Kd = 1.3
This erratum does not affect any discussion and conclusions reported in the paper. The authors apologize for these errors in the paper. Dorinel Verdes has been added as an author. He has contributed to work out this correction.
Figure 6. The average fluorescence lifetime changes between free donor and acceptor bound donor against the donor concentrations. © 2013 American Chemical Society
Published: May 28, 2013 6857
dx.doi.org/10.1021/jp403771p | J. Phys. Chem. B 2013, 117, 6857−6857
