Adsorption kinetics of an engineered gold binding Peptide by surface plasmon resonance spectroscopy and a quartz crystal microbalance.

Department of Chemistry, University of Washington Seattle, Seattle, Washington, United States
Langmuir (Impact Factor: 4.38). 09/2006; 22(18):7712-8. DOI: 10.1021/la0606897
Source: PubMed

ABSTRACT The adsorption kinetics of an engineered gold binding peptide on gold surface was studied by using both quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) spectroscopy systems. The gold binding peptide was originally selected as a 14-amino acid sequence by cell surface display and then engineered to have a 3-repeat form (3R-GBP1) with improved binding characteristics. Both sets of adsorption data for 3R-GBP1 were fit to Langmuir models to extract kinetics and thermodynamics parameters. In SPR, the adsorption onto the surface shows a biexponential behavior and this is explained as the effect of bimodal surface topology of the polycrystalline gold substrate on 3R-GBP1 binding. Depending on the concentration of the peptide, a preferential adsorption on the surface takes place with different energy levels. The kinetic parameters (e.g., K(eq) approximately 10(7) M(-1)) and the binding energy (approximately -8.0 kcal/mol) are comparable to synthetic-based self-assembled monolayers. The results demonstrate the potential utilization of genetically engineered inorganic surface-specific peptides as molecular substrates due to their binding specificity, stability, and functionality in an aqueous-based environment.

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    • "More than 50 sequences of inorganic-binding polypeptides were identified, and the peptide having the amino acid sequence of MHGKTQATSGTIQS was studied (Brown, 1997; Sarikaya et al., 2004). Interestingly, the GBP sequence does not contain cysteine, which is known to form a covalent bond with gold (Brown, 1997); the adsorption kinetics of GBP on the gold surface was reported using surface plasmon resonance (SPR) spectroscopy (Tamerler FEMS Microbiol Lett 293 (2009) 141–147 c et al., 2006). Whereas many proteins and self-assembled monolayers bind to the gold surface via thiol linkage (Zhang et al., 1996; Tarek et al., 1999), the nature of GBP binding is thought to be different. "
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    ABSTRACT: Cell surface display was used as a strategy to display the gold-binding polypeptide (GBP) fusion protein on the surface of Escherichia coli, and consequently to immobilize the cells on the gold surface. The DNA encoding the GBP was fused to the truncated fadL gene and was expressed by the tac promoter. For the display of the core streptavidin (cSA) of Streptomyces avidinii, the cSA gene was fused to the truncated oprF gene. After the dual display of FadL-GBP and OprF-cSA on the surface of E. coli, binding of cells on the gold surface and the interaction of OprF-cSA with the biotin-horseradish peroxidase (HRP) were studied by surface plasmon resonance (SPR) analysis. Cells displaying the FadL-GBP fusion protein could be immobilized on the SPR sensor chip as shown by the SPR angle shift of 0.5 degrees , which was stably bound at least for 60 h with a washing solution. When the FadL-GBP and OprF-cSA fusion proteins were displayed on the same cell surface, the former was used to immobilize the cells on the gold surface and the latter was used for the interaction studies with the biotin-HRP, which demonstrates that the strategy should be useful for developing whole-cell biosensor chips.
    FEMS Microbiology Letters 03/2009; 293(1):141-7. DOI:10.1111/j.1574-6968.2009.01525.x · 2.72 Impact Factor
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    • "The amount of bound peptide on the surface was determined by the shift in the refractive index dip position. A higher shift reflects high amount of peptide adsorption and a sharp increase reveals a faster binding (Chang et al., 2006; Tamerler et al., 2006). "
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    ABSTRACT: MOTIVATION: The discovery of solid-binding peptide sequences is accelerating along with their practical applications in biotechnology and materials sciences. A better understanding of the relationships between the peptide sequences and their binding affinities or specificities will enable further design of novel peptides with selected properties of interest both in engineering and medicine. RESULTS: A bioinformatics approach was developed to classify peptides selected by in vivo techniques according to their inorganic solid-binding properties. Our approach performs all-against-all comparisons of experimentally selected peptides with short amino acid sequences that were categorized for their binding affinity and scores the alignments using sequence similarity scoring matrices. We generated novel scoring matrices that optimize the similarities within the strong-binding peptide sequences and the differences between the strong- and weak-binding peptide sequences. Using the scoring matrices thus generated, a given peptide is classified based on the sequence similarity to a set of experimentally selected peptides. We demonstrate the new approach by classifying experimentally characterized quartz-binding peptides and computationally designing new sequences with specific affinities. Experimental verifications of binding of these computationally designed peptides confirm our predictions with high accuracy. We further show that our approach is a general one and can be used to design new sequences that bind to a given inorganic solid with predictable and enhanced affinity.
    Bioinformatics 12/2007; 23(21):2816-22. DOI:10.1093/bioinformatics/btm436 · 4.62 Impact Factor
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    ABSTRACT: The overarching goals in this DURINT project have been: 1. Combinatorial selection and post-selection engineering polypeptides that have specific affinity to inorganic surfaces (GEPI); 2. Understanding the nature of protein molecular binding on inorganic surfaces using experimental and theoretical tools; 3. Use these polypeptides as molecular tools to assemble and make nanostructures, and 4. To develop hybrid complex materials with nanoarchitectures, composed of peptides, polymers and nanoinorganics for electronic, photonic, and magnetic applications The accomplishments included: Selection of GEPI using phage and cell surface display protocols; Post-selection engineering for tailored binding and improved functionalities; In-silico design of Peptides; GEPI binding characteristics using FM, SPR, QCM, and AFM; Assessing chemical binding & conformation of using XPS, TOF-SIMS and ss-NMR; Development of GEPI-designer protein conjugates and assemblers/immobilizers; Conjugation of GEPI and functional monomers designed and synthesized; Modeling of molecular conformation of GEPI on solids; Permissive site analysis on DNA binding and fluorescent proteins for clones for genetic engineering; Synthesis of inorganics for control of size and composition using GEPIs; Control inorganic architecture and immobilization using GEPIs & DNA templates; Development of protein-based nanomasks, GEPI and viral based templates for nanophotonics, including potential use by the DoD applications.
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