Analysis of the activation of acetylcholinesterase by carbon nanoparticles using a monolithic immobilized enzyme microreactor: role of the water molecules in the active site gorge

Figures & data

Figure 1.  Relative AChE Activity (RAA) (i.e. AChE activity relative to the value at x = 0) at x (g/L) of SWNTs versus time (s).

Figure 2.  Relative AChE Activity (RAA) for the immobilized enzyme (i.e. the AChE activity relative to the value at x = 0) versus x (mg/mL) of CNPs.

Figure 3.  AChE catalysis rate (ΔA/min) versus substrate (ATCh) concentration at 0 and 0.04 mg/mL of SWNTs (Michaelis–Menten curve).

Figure 4.  1/velocity (1/V) versus 1/[substrate] (1/[ATCh]) at A) x =0 and B) x = 0,04 mg/mL of SWNTs (Lineweaver–Burk plot).

Table 1.  Michaelis constant (K_m mmol), the maximum velocity (V_max mmol/min), the catalytic constant (k_cat mmol/min/U) and the catalytic efficiency (k_cat/K_m) for x mg/mL of CNPs.

CNPs (mg/mL)	Km mmol	Vmax mmol/min	kcat mmol/min/U	kcat/Km
x = 0	34	191.4	54.7	1.6
SWNTs (x = 0.04)	30	244.2	69.8	2.3
SWNTs-COOH (x = 0.04)	32	207.9	59.4	1.9
C60 (x = 0.04)	33	201.3	57.5	1.7

Table 2.  Activation energy (Ea), enthalpy (ΔH*) and entropy (ΔS*)of attaining the reaction transition state (AChE-Substrate, ATCh) versus x mg/mL of single carbon nanotubes (SWNTs).

SWNTs	Ea kJ/mol	ΔH* kJ/mol	ΔS*J/mol/K
x = 0	54.2	21.8	–104
x = 0.04 mg/mL	53.3	30.8	–72

Figure 5.  Ln(Vmax/T) vs 1/T (K^-1) for x = 0 and 0.04 mg/ml of SWNTs (Arrhenius plot).