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Figure 2 | EJNMMI Research

Figure 2

From: Influence of d-glutamine and d-glutamic acid sequences in optical peptide probes targeted against the cholecystokinin-2/gastrin-receptor on binding affinity, specificity and pharmacokinetic properties

Figure 2

The optical probes QE and bivQ showed specific binding and internalization in A431/CCK2R cells. We found intracellular uptake into A431/CCK2R cells at 37°C for the probes (a) QE and (b) bivQ and (c) cell membrane binding at 4°C (exemplarily for bivQ). (d) A431/WT cells showed no probe uptake at 37°C (exemplarily for QE). (e) Native A431/CCK2R showed no fluorescence in the NIR spectrum. (f) Similar internalization into A431/CCK2R cells was observed for the probe dQ-MG-754 [20] at 37°C. Displayed are representative fluorescence microscopy images of n = 3 experiments. Colour coding: red, DY-754 spectrum; green, cell membrane stain WGA-555; blue, cell nuclei stained with Hoechst 33258. Bars measure 100 μm.

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