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Interaction Forces between Colloids and Protein-Coated Surfaces Measured Using an Atomic Force Microscope

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Department of Civil and Environmental Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802
Cite this: Environ. Sci. Technol. 2005, 39, 10, 3592–3600
Publication Date (Web):April 2, 2005
https://doi.org/10.1021/es048377i
Copyright © 2005 American Chemical Society

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    Abstract

    Bacterial surfaces contain proteins, polysaccharides, and other biopolymers that can affect their adhesion to another surface. To better understand the role of proteins in bacterial adhesion, the interactions between two different model colloids (glass beads and carboxylated latex microspheres) and four proteins covalently bonded to glass surfaces were examined using colloid probes and an atomic force microscope (AFM). Adhesion forces between an uncoated glass colloid probe and protein-coated surfaces, measured in retraction force curves, decreased in the order poly-d-lysine > lysozyme > protein A > BSA. This ordering was consistent with the relative calculated charges of the proteins at neutral pH and the ζ-potentials measured for glass beads and latex microspheres coated with these proteins. When the glass bead was coated with a protein (BSA), overall adhesion forces between the protein-coated colloid and the protein-coated surfaces were reduced, and the adhesion force for each protein decreased in the same order observed in experiments with the uncoated glass bead. When latex colloid probes were coated with BSA, adhesion forces were significantly larger than those measured with BSA-coated glass colloid probes under the same conditions, demonstrating that the nature of the underlying colloid can affect the measured interaction forces. In addition, the adhesion forces measured with the BSA-coated latex colloid increased in a different order (BSA ≤ lysozyme < protein A < poly-d-lysine) than that observed using the BSA-coated glass colloid. It was also found that increasing the solution ionic strength consistently decreased adhesion forces. This result is contrary to the general observation that bacterial adhesion increases with ionic strength. It was speculated that conformational changes of the protein produced this decrease in adhesion with increased ionic strength. These results suggest the need to measure nanoscale adhesion forces in order to understand better molecular scale interactions between colloids and surfaces.

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     Corresponding author phone:  814-863-7908; fax:  814-863-7304; e-mail:  [email protected].

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    54. R.M. Goulter, I.R. Gentle, G.A. Dykes. Issues in determining factors influencing bacterial attachment: a review using the attachment of Escherichia coli to abiotic surfaces as an example. Letters in Applied Microbiology 2009, 49 (1) , 1-7. https://doi.org/10.1111/j.1472-765X.2009.02591.x
    55. Li-Chong Xu, Pranav Soman, Aashiish Agnihotri, Christopher A. Siedlecki. Atomic Force Microscopy Methods for Characterizing Protein Interactions with Microphase-Separated Polyurethane Biomaterials. 2009, 43-67. https://doi.org/10.1007/978-0-387-98161-1_3
    56. Daniel Johnson, Nidal Hilal, W. Richard Bowen. Basic Principles of Atomic Force Microscopy. 2009, 1-30. https://doi.org/10.1016/B978-1-85617-517-3.00001-8
    57. Nidal Hilal, W. Richard Bowen, Daniel Johnson, Huabing Yin. AFM and Development of (Bio)Fouling-Resistant Membranes. 2009, 139-171. https://doi.org/10.1016/B978-1-85617-517-3.00005-5
    58. Daisuke HIRAIWA, Kanjiro TORIGOE, Tomokazu YOSHIMURA, Kunio ESUMI. Interaction Forces between BSA Adsorbed Layer on Amino-Thiolated Gold Surfaces. Shikizai Kyokaishi 2008, 81 (1) , 2-9. https://doi.org/10.4011/shikizai.81.2
    59. Yuncheng Liang, Nidal Hilal, Paul Langston, Victor Starov. Interaction forces between colloidal particles in liquid: Theory and experiment. Advances in Colloid and Interface Science 2007, 134-135 , 151-166. https://doi.org/10.1016/j.cis.2007.04.003
    60. Michael B. Salerno, Xu Li, Bruce E. Logan. Adhesion characteristics of two Burkholderia cepacia strains examined using colloid probe microscopy and gradient force analysis. Colloids and Surfaces B: Biointerfaces 2007, 59 (1) , 46-51. https://doi.org/10.1016/j.colsurfb.2007.04.014
    61. Li-Chong Xu, Christopher A. Siedlecki. Effects of surface wettability and contact time on protein adhesion to biomaterial surfaces. Biomaterials 2007, 28 (22) , 3273-3283. https://doi.org/10.1016/j.biomaterials.2007.03.032
    62. M. Adoue, P. Bacchin, S. Lorthois, D. Combes, P. Schmitz, M. Mercier-Bonin. Experimental Methodology for Analysing Macromolecular Interactions in the Context of Marine Bacterial Adhesion to Stainless Steel. Chemical Engineering Research and Design 2007, 85 (6) , 792-799. https://doi.org/10.1205/cherd06067
    63. Daniel J. Johnson, Nicholas J. Miles, Nidal Hilal. Quantification of particle–bubble interactions using atomic force microscopy: A review. Advances in Colloid and Interface Science 2006, 127 (2) , 67-81. https://doi.org/10.1016/j.cis.2006.11.005
    64. Li-Chong Xu, Bruce E. Logan. Adhesion forces between functionalized latex microspheres and protein-coated surfaces evaluated using colloid probe atomic force microscopy. Colloids and Surfaces B: Biointerfaces 2006, 48 (1) , 84-94. https://doi.org/10.1016/j.colsurfb.2006.01.012
    65. Yoshinori Iiguni, Hitoshi Watarai. Electromagnetophoretic Measurements of Adsorption Forces of Polystyrene Microparticles on Silica Surfaces in Surfactant Solutions. Bulletin of the Chemical Society of Japan 2006, 79 (1) , 47-52. https://doi.org/10.1246/bcsj.79.47
    66. T. Vladkova. Surface Modification Approach to Control Biofouling. , 135-163. https://doi.org/10.1007/978-3-540-69796-1_7

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