Binding Constant of the Cell-shaped Cavity Formed on a Polymer for Escherichia coli O157

Abstract

The binding constant of receptors for small molecules, proteins, or antibodies is usually determined based on the concentrations of the ligand, receptor, and their complexes. The binding constant is used as a measure of the affinity between the ligand and the receptor. In the present study, we introduce a procedure to determine the binding constant of a cell-shaped cavity formed on a polymer by molecular imprinting for a whole cell. To determine the binding constant, we clarified the numbers of cavities and cells, based on the fluorescence of a single cell, and defined their concentrations. We successfully determined the binding constant of the complementary cavity for a whole cell (1.1 × 10 5 M-1). This is the first report to describe the binding constant of a complementary cavity for a whole cell.

Evaluation of Surface Structure of Escherichia coli Using Polypyrrole Matrix

“…Previously, the binding constant, Ka, was reported as 1.1 × 10 5 M -1 , which is a good binding affinity between target cells and complementary cavities. 22 Nevertheless, E. coli O rough cells having no O-antigen on their surface were captured in the vertical direction regardless of round-shaped or bacilliform cavities. Therefore, we conclude that the O-antigen-imprinted cavity worked as an artificial antibody which bound strongly to the O-antigen.…”

“…PPy was formed on nafion-coated microspheres (mean diameter: 5.0 μm) by chemical oxidation in an aqueous medium containing E. coli cells. 16,22 We supposed that cells adhered to the microspheres as the polymerization progressed and acted as dopant anions with a negative zeta potential (∼ -30 mV). SEM and fluorescence microscopy confirmed that the cells were immobilized in the PPy film ( Figs.…”

“…To clarify the difference in the function of the cavities formed by E. coli with and without O-antigen, we performed a rebinding test of the cell-imprinted microsphere. The E. coli O rough cellimprinted microspheres were added into the SYTO9-labeled E. coli O rough suspensions (2.0 × 10 7 cells mL -1 ) and then the mixture was incubated at 298 K. 16,22 The fluorescence intensity of the supernatant (I) at 500 nm obtained was normalized by that of E. coli O rough suspension without microspheres (I0). The cell-imprinted microspheres can capture the target cells spontaneously.…”

Exploring the Effects of Acid Fuchsin on Microscopic Morphology and Properties for Polypyrrole

“…Polypyrrole (PPy), one of the most popular polymers among the family of conducting polymers, has superior performance such as environmental stability and biocompatibility [11]. And it can be used in many potential applications including electrode materials of supercapacitors and batteries [12][13][14], sensors [15,16], drug delivery [17,18], biological ion detection, and electromagnetic shielding materials [19].…”

Biosensors Using an Antibody as a Recognition Element

“…Shan et al described determining the binding constant of the complementary cavity for a whole cell. 8 They introduce a procedure to determine the binding constant of a cell-shaped cavity formed on a polymer by molecular imprinting for a whole cell. Lv et al reported the determination of an aryl hydrocarbon receptor (AhR) coupled with anthracene (Ant) that exhibits genotoxicity and carcinogenicity based on an indirect competition enzyme linked immunosorbent assay using an AhR-Ant antibody.…”