Modified peptide monolayer binding His-tagged biomolecules for small ligand screening with SPR biosensors

Abstract

A peptide self-assembled monolayer (SAM) was designed to bind His-tagged biomolecules for surface plasmon resonance (SPR) bioanalysis, which was applied for the determination of K(d) for small ligand screening against CD36. Nonspecific adsorption could be minimized using penta- and hexa-peptide monolayers. In particular, monolayers consisting of 3-mercaptopropionyl-leucinyl-histidinyl-aspartyl-leucinyl-histidinyl-aspartic acid (3-Mpa-LHDLHD) exhibited little (12 ng cm(-2)) nonspecific adsorption in crude serum. Modification of this peptide monolayer with Nα,Nα-bis(carboxymethyl)-L-lysine gave a surface competent for binding His-tagged proteins, as demonstrated using enzyme (human dihydrofolate reductase), protein/antibody and receptor (CD36) examples. Immobilization featured chelation of copper and the His-tagged protein by the peptide monolayer, which could be recycled by removing the copper using imidazole washes prior to reuse.

Naked-eye nanobiosensor for therapeutic drug monitoring of methotrexate

“…30 The samples were purified by repeated rinsing cycles of suspension-centrifugation at 15 000 RPM in acetone and dried, then dissolved in chloroform to produce a highly concentrated suspension (∼10 13 NP mL −1 ). [31][32][33][34] The prisms were then cleaned with ethanol and water. This excess was necessary to avoid plasmon coupling of neighbouring Au NPs in the sensing layer in absence of the competition assay.…”

“…A small excess of unbound PS was added to the suspensions to ensure proper spacing between the Au NPs. 31 The remaining activated carboxyl groups were deactivated for 5 min with 1 M ethanolamine at pH 8.5. Dove prisms (20 × 12 × 3 mm) were cleaned in hot piranha solution for 90 min (Caution!…”

Surface plasmon resonance based biosensor: A new platform for rapid diagnosis of livestock diseases

“…The site-specific immobilization is also done by utilizing different biochemical affinity reaction, e.g., biotin-avidin/streptavidin reaction [16], histidine cheated metal ion interaction [17], or DNA hybridization [18]. In SPR biosensors, peptides are now extensively used as biorecognition materials for the study of protein structure and function [19] and also used for the detection of heavy metals and small ligand [20]. Immobilization of peptides to the metallic surface is done by electrostatic attraction and amine- or thiol-based covalent coupling.…”

Immunodiagnostics and immunosensor design (IUPAC Technical Report)

“…The His-tag-assisted method showed an enhanced signal, a 10-fold higher sensitivity, and a wider linear range. As an interesting alternative, the His-tagged binding surface layer can also be constructed by peptide self-assembled monolayer (SAM) as demonstrated by Bolduc and co-workers [71]. Significant reduction of nonspecific adsorption of non-analyte constituents of crude serum was reported using penta-and hexa-peptide monolayers.…”