title: Chemisorptions of bacterial receptors for hydrophobic amino acids and sugars on gold for biosensor applications: a surface plasmon resonance study of genetically engineered proteins.
abstract: This paper demonstrates potential applications of two periplasmic receptor proteins from E. coli as sensing elements for biosensors using the surface plasmon resonance (SPR) technique. These molecules, namely the aspartate to cysteine mutant of the leucine-specific receptor (LS-D1C) and the glutamine to cysteine mutant of the D-glucose/D-galactose receptor (GGR-Q26C) proteins, are chemisorbed on a thin (approximately 40 nm) Au film in neutral K2HPO4 buffers. Using angle and time resolved SPR measurements; we show that adsorption behaviors of both proteins are dominated by diffusion-free second order Langmuir kinetics. We also show that the protein-modified Au films exhibit measurable SPR shifts upon binding to their respective target ligands. According to these SPR data, the kinetics of ligand binding for both LS-D1C and GGR-Q26C are governed by irreversible first order diffusion limited Langmuir model. The utility of the SPR technique for studying reactions of biological molecules is further illustrated in this work.
authors: Department for Chemistry, Clarkson University, PO Box 5810, Potsdam, NY 13699, USA.
authors: Linda A
authors: LA
authors: Luck
authors: Michael J
authors: MJ
authors: Moravan
authors: John E
authors: JE
authors: Garland
authors: Branka
authors: B
authors: Salopek-Sondi
authors: Dipankar
authors: D
authors: Roy
mesh_terms: D000327:Adsorption; D019943:Amino Acid Substitution; D000596:Amino Acids / Q000032:analysis / Q000737:chemistry; D001426:Bacterial Proteins; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002241:Carbohydrates / Q000032:analysis / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis / Q000737:chemistry; D004566:Electrodes; D005690:Galactose / Q000032:analysis / Q000737:chemistry*; D005947:Glucose / Q000032:analysis / Q000737:chemistry*; D006046:Gold; D057927:Hydrophobic and Hydrophilic Interactions; D007930:Leucine / Q000032:analysis* / Q000737:chemistry; D016297:Mutagenesis, Site-Directed; D033902:Periplasmic Binding Proteins; D017459:Receptors, Amino Acid / Q000737:chemistry* / Q000235:genetics; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D002241:Carbohydrates; D020099:Coated Materials, Biocompatible; D033902:Periplasmic Binding Proteins; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; C039707:galactose receptor; C027786:glucose receptor; C034181:leucine receptor; D006046:Gold; D007930:Leucine; D005947:Glucose; D005690:Galactose