ABSTRACT
RGD peptide sequence is an effective cell recognition motif and used to enhance the cell adhesion on desired solid material for cell immobilization. We have synthesized CRGD, CRGD-multiple-armed peptide (MAP), RGD-MAP-C and evaluated their comparative efficacy for cell immobilization. Each peptide was assembled on gold surface and investigated by the atomic force microscopy (AFM) technique in the contact mode. The viability of immobilized animal cells was examined by an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Our results showed that RGD-MAP-C in comparison to others was the most effective proliferation of cells on the gold surface. The goal of this present work is integration to the nano-pattern cell chip bioplatform for biomedical assays or provide valuable insights into cell biology and design of biomaterials. This RGD-MAP-C can be applicable to the nano-pattern cell chip platform.
Subject(s)
Cells, Immobilized , Cells/metabolism , Cysteine/chemistry , Oligopeptides/chemistry , Amino Acid Sequence , Animals , Cell Division , Cell Survival , Cells/ultrastructure , Cells, Immobilized/ultrastructure , HeLa Cells , Humans , Image Processing, Computer-Assisted , Microscopy/instrumentation , Microscopy/methods , Microscopy, Atomic Force , Oligopeptides/genetics , Tetrazolium Salts/metabolism , Thiazoles/metabolismABSTRACT
We fabricated a self-assembled monolayer (SAM) of a chimeric protein created as a novel model protein for an artificial light-harvesting complex (LHC) composed of two proteins, cytochrome b(562) (cytb(562)) mutated for SAM fabrication (cytb(562), N22C, G82C) and enhanced green fluorescent protein (EGFP). The SAM formation of chimeric protein on a single-crystalline Au(111) substrate was confirmed by atomic force microscopy (AFM) measurement. The rectified photocurrent of the chimeric protein SAM on a gold substrate was detected by light-illumination scanning tunneling microscopy (LI-STM) co-operated with a lock-in technique. The photocurrent generation of the chimeric protein SAM was wavelength-specific to the light-illumination (488 nm), which indicated that the EGFP part of the chimera plays a role as a sensitizer in the photo-induced electron transfer process.
Subject(s)
Biosensing Techniques/instrumentation , Cytochrome b Group , Escherichia coli Proteins , Recombinant Fusion Proteins , Models, Biological , Photosynthesis/physiology , Spectrophotometry , Time FactorsABSTRACT
Transparent protein film of iron-free cytochrome c (Cyt. c) was successfully manufactured by electrospray deposition (ES) method and the properties of the protein film were investigated. Excursion temperature dependence of spectral hole profiles in the photochemical hole burning for the iron-free Cyt. c in protein film and in glassy solution was investigated and compared with that of iron-free porphyrin embedded in a synthetic polymer film to clarify photochemical properties of electrospray deposited protein film. The spectral holes of iron-free porphyrin were thermally more stable in Cyt. c than in polymer, indicating compact packing of the chromophore in the protein. The ES-deposited iron-free Cyt. c in protein film showed less stable spectral hole than that in glassy solution. This difference is attributable to the electrospray deposition process of the protein involving ionization and to subsequent cross-linking of protein molecules.
