title: Study on orientation of immunoglobulin G on protein G layer.
abstract: A comparative study of immunoglobulin G (IgG) immobilization was performed, both on a thiolated protein G layer, where this immobilization was due to affinity binding with an Fc fragment of IgG, and on 11-mercaptoundecanoic acid (11-MUA), where the immobilization was due to chemical bonding. The change of IgG layer formation on the two base layers as a function of the IgG concentration was investigated by surface plasmon resonance (SPR), atomic force microscopy (AFM) in a non-contact mode, and spectroscopic ellipsometry (SE). It was observed that the IgG layer was immobilized more evenly on the thiolated protein G layer than on the 11-MUA layer, based on the SPR measurements. The surface topology analysis by AFM indicated that the IgG layer was immobilized on the protein G layer according to the envelope profile of the base layer. Based on the SE analysis, it was determined that the IgG layer thickness on the thiolated protein G layer increased with increasing IgG concentration. Based on the above analyses, the scheme for orientation of IgG immobilized on the thiolated protein G layer was proposed.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Sogang University, 1 Sinsu-Dong, Mapo-Gu, Seoul 121-742, South Korea.
authors.forename: Young Min
authors.initials: YM
authors.lastname: Bae
authors.forename: Byung-Keun
authors.initials: BK
authors.lastname: Oh
authors.forename: Woochang
authors.initials: W
authors.lastname: Lee
authors.forename: Won Hong
authors.initials: WH
authors.lastname: Lee
authors.forename: Jeong-Woo
authors.initials: JW
authors.lastname: Choi
mesh_terms: D015374:Biosensing Techniques; D006046:Gold; D007074:Immunoglobulin G; D018625:Microscopy, Atomic Force; D009419:Nerve Tissue Proteins; D013438:Sulfhydryl Compounds / Q000378:metabolism; D020349:Surface Plasmon Resonance
chemical_list: C029152:G-substrate; D007074:Immunoglobulin G; D009419:Nerve Tissue Proteins; D013438:Sulfhydryl Compounds; D006046:Gold