Kinetic modeling and analysis of a vesicle system for immunosensor development.
A novel mechanism is presented for immunosensor development that uses an immunological competition reaction in a vesicle system. This system consists of a suspension of reconstituted vesicles, channel agonist, protein linker to block the channels, voltage sensitive dye and analyte to be detected. In the proposed mechanism analyte serves a catalytic role as individual analytes competitively displace multiple channel linkers through association with one channel, dissociation and new associations with other channels. When one channel opens on a vesicle a permanent Nernst potential develops for that vesicle leading to fluorescence of voltage sensitive dyes. The time constant of the redistribution from linker-channel form to analyte-channel form is 0.92/k4 (k4 is the off-rate constant for the analyte-channel association) in the region of analyte concentrations less than 10(-9) M. Kinetic analyses show that several factors, including concentration of analyte or linker, number of channels per vesicle, on-rate or off-rate constant of the linker-channel and on-rate constant of analyte-channel complexes have significant effects on the minimum signal response time.
Yu
Y Y
YY
Department of Chemical Engineering, Washington State University, Pullman 99164-2710, USA.
Van Wie
B J
BJ
Koch
A R
AR
Moffett
D F
DF
Davis
W C
WC
D000937:Antigen-Antibody Reactions; D015374:Biosensing Techniques; D006801:Humans; D007700:Kinetics; D008954:Models, Biological