Figure 5

Concentration values of the secretases at intermediate levels of SORLA. Simulations of the influence of intermediate levels of SORLA on APP processing on the amount of α-secretase (A-F) and β-secretase (G-L) concentration. The term “used” refers to the complex formation of the secretases and APP, while the term “free” refers to the secretases that are not bound in a complex. There are five intermediate levels of SORLA, namely, 0% (solid line), 3%, 12%, 30%, and 100% (dashed line) of SORLA_Tot (where SORLA_Tot = 2.43 x 10⁵ fmol). When there is only solid line in a plot, it is because solid and dashed lines are superimposed. Starting from the first column, there shows the amount of α- (A) and β-secretase (G) that is free in monomer processing. In the second column, it shows the amount of α- (B) and β-secretase (H) that is free in dimer processing. The amount of α- (C) and β-secretase (I) used in monomer processing are shown in the third column, whereas those used in dimer processing (D, J) are shown in the fourth column. In the fifth column, there shows the total amount of α- (E) and β-secretase (K) that is free (blue line) and used (orange line) in the system. Lastly, there is the total amount of α- (F) and β-secretase (L) in monomer (blue line) and in dimer (orange line) processing of the system. The black lines in (E, F) and in (K, L) are the estimated total amount of α-and β-secretase, respectively. In particular, the black line in (E, K) represents the sum of the secretase concentration depicted by the blue and orange lines, while the one in (F, L) indicates the sum of the secretase concentration depicted by the red and green lines. Notice that the solid and dashed lines for both blue and orange colors deviates in (K). This, however, is not the case in (E).