Classification of the mode of inhibition of high-affinity choline uptake using capillary electrophoresis with electrochemical detection at an enzyme-modified microelectrode

A Changed Electrode Reaction Mechanism between the Nano‐ and Macroscales

“…Using fenoprofen as a model compound that strongly interacts with TM‐β‐CD, a series of double reciprocal plot showed a trend of increasing slope values with almost a constant intercept. This trend is in accordance with the observation described in the literature 25, suggesting that the inhibition observed in chiral separation of PROFs is a competitive inhibition. Future studies will be focused on the combined use of the same dual chiral selector ( i.e.…”

“…For example, under the conditions of 0.8 or 1.0 mM L ‐UCLB, and the concentrations of TM‐β‐CD at 0.0 or 1.0 mM in the CE buffers, it took more than 2 h for the fenoprofen peaks to elute out and caused greater error on the migration time than at other concentration of L ‐UCLB. However, this relatively high deviation is acceptable in the literature of biochemistry when determining the type of inhibition 25. The data for S ‐fenoprofen showed the same trends for the slopes and intercepts with the greatest deviation at 0.8 mM L ‐UCLB.…”

“…As we discussed in Section 3.2, shown and listed in Fig. 4 and Table 4, we believe that the pattern of the double‐reciprocal plots with increasing slope values but constant intercept values suggests that the inhibition happened between L ‐UCLB and the (TM‐β‐CD)–(fenoprofen) complex is similar to the enzyme–substrate–inhibitor systems 25, and mainly it is a type of competitive inhibition.…”

“…The data generated in Table 4 can be used to obtain the inhibition constant between L ‐UCLB and fenoprofen ( K i ) from a secondary plot of which the x ‐axis is the concentration of the L ‐UCLB and y ‐axis is the slope values of the double‐reciprocal plots obtained from Table 4 18, 25. Here the inhibition constant is the dissociation constant of the ( L ‐UCLB)–(fenoprofen) complex 17, 18.…”

Synthesis and characterization of luminescent cadmium selenide/zinc selenide/zinc sulfide cholinomimetic quantum dots

“…In our laboratory, analyses of ACh and Ch were achieved in vitro and in vivo by use of capillary electrophoresis with electrochemical detection where sample sizes of 5-10 nL and attomole detection limits were possible. [14][15][16][17][18][19][20] These methods were also valuable to monitor small timedependent changes in Ch concentrations in near real-time during the transport of Ch through CHT. Determination of K I and IC 50 values, and the mode of inhibition for inhibitors of CHT were then possible.…”