Figure 5 - Urea dependence of ANS binding by bovine trypsinogen measured by intensity of ANS fluorescence at 480 nm (excitation at 350 nm). The samples were incubated for 15 min. The excitation and emission bandwidths were fixed at 2 nm each and a 1-cm path length quartz cuvette was used for all measurements. Protein concentrations were 500 ÁM for all assays and temperature was 25oC.