Direct immobilization of cupredoxin azurin modified by site-directed mutagenesis on gold surface

• Published in: Ultramicroscopy Vol. 108; no. 10; pp. 1390 - 1395
• Main Authors: Kim, Sang-Uk, Kim, Young Jun, Choi, Shin-Geon, Yea, Cheol-Heon, Singh, Ravindra P., Min, Junhong, Oh, Byung-Keun, Choi, Jeong-Woo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.09.2008
• Subjects: Adsorption; Azurin - chemistry; Azurin - genetics; Cyclic voltammetry; Electrochemistry; Gold - chemistry; Microscopy, Scanning Tunneling - methods; Mutagenesis, Site-Directed - methods; Pseudomonas aeruginosa - enzymology; Pseudomonas aeruginosa - genetics; Scanning tunneling microscopy; Site-directed mutagenesis; Surface plasmon resonance; Surface Plasmon Resonance - methods; Cyclic voltammetry; Scanning tunneling microscopy; 81.16.Dn; 81.07.Nb; Site-directed mutagenesis; 07.79.−v; Surface plasmon resonance; 68.37.Ef
• ISSN: 0304-3991; 1879-2723
• DOI: 10.1016/j.ultramic.2008.04.048

For making efficient bioelectronic device, we have developed novel immobilization method of cupredoxin azurin modified on gold (Au) surface. A recombinant protein with cysteine residue by using site-directed mutagenesis was designed and then directly immobilized on Au surface without any chemical linker. The immobilization of the functionalized protein is confirmed by surface plasmon resonance (SPR) and its surface morphology is analyzed by scanning tunneling microscopy (STM). The immobilization efficiency has been increased about 75.6%, as compared to that of wild-type azurin. The electrochemical property of the fabricated thin film was investigated by the cyclic voltammetry (CV). As a result, cysteine-modified azurin can be used for making high-quality protein film, and applied to the fabrication of nano-scale bioelectronics.