Fig. 6. Incubation of HeLa cells with (a) HSA/GlcNAc-HHPO and (b) HSA/GlcNPr-HHPO at different concentrations with high (80–90% per well) and low (40–50% per well) cell densities for 1,2 and 4 h. Normalized fluorescence intensity of HeLa cells incubated with HSA/GlcNAc-HHPO (50 µM/50 µM) and HSA/GlcNPr-HHPO (50 µM/50 µM) in the presence of (c) PugNAc and (d) TMG with different concentrations for 2 h. All measurements were done in a microplate reader with an excitation wavelength of 550 nm (the fluorescence emission intensity at 598 nm was measured). Statistical analysis was performed using two-way ANOVA and Dunnett's multiple comparisons test (n = 3; the P values shown in the diagrams were obtained with respect to the group in which the inhibitor was absent).