title: Nanoscale film formation of recombinant azurin variants with various cysteine residues on gold substrate for bioelectronic device.
abstract: Nanoscale film fabrication of recombinant azurin variants with various cysteine residues on gold substrate was developed without any surface modification for bioelectronic device. We have modified azurin with different number of cysteine residues at its amino acid chain based on site-directed mutagenesis. The resulting recombinant protein, azurin, retained its original redox property in the same manner as native azurin. Recombinant azurin was immobilized on Au substrate by strong affinity between thiol of cysteine and gold. The orientations of recombinant azurin with various cysteine residues immobilized on the Au substrate were analyzed by fluorescence microscope, scanning tunneling microscope, and surface plasmon resonance. Our data revealed that binding activity of recombinant azurin with three cysteine residues on the Au substrate significantly increased in comparison to single residue azurin. Immobilization method of highly oriented recombinant azurin based on cysteine-modification could be useful for the nanoscale film fabrication of nanobiochip.
authors.affiliation: Interdisciplinary Program of Integrated Biotechnology, Sogang University, #1 Shinsu-Dong, Mapo-Gu, Seoul 121-742, Korea.
authors.forename: Sang-Uk
authors.initials: SU
authors.lastname: Kim
authors.forename: Jin-Ho
authors.initials: JH
authors.lastname: Lee
authors.forename: Taek
authors.initials: T
authors.lastname: Lee
authors.forename: Junhong
authors.initials: J
authors.lastname: Min
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Choi
mesh_terms: D019943:Amino Acid Substitution; D001400:Azurin / Q000737:chemistry* / Q000235:genetics; D015374:Biosensing Techniques / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003460:Crystallization / Q000379:methods; D003545:Cysteine / Q000737:chemistry*; D004581:Electronics / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006801:Humans; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008567:Membranes, Artificial; D008968:Molecular Conformation; D009154:Mutation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation; D010316:Particle Size; D011994:Recombinant Proteins / Q000737:chemistry; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D046911:Macromolecular Substances; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D001400:Azurin; D006046:Gold; D003545:Cysteine