Ellipsometric investigation of the effect of potential on blood protein conformation and adsorbance

Morrissey, B. W.; Smith, Leslie E.; Stromberg, Robert R.; Fenstermaker, Carl A.

doi:10.1016/0021-9797(76)90121-1

Cited by 70 publications

(20 citation statements)

References 22 publications

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“…The influence of an applied electric potential on the adsorption of charged macromolecules (mainly proteins) has been the subject of several previous investigations (19,20,(30)(31)(32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44). Although most of these studies note an influence of substrate potential on adsorption, changes are typically within a factor of two or so, and to our knowledge no continuous adsorption has been reported.…”

Section: Discussionmentioning

confidence: 99%

Continuous polyelectrolyte adsorption under an applied electric potential

Ngankam

Tassel

2007

Proc. Natl. Acad. Sci. U.S.A.

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Interactions between charged macromolecules (e.g., proteins, nucleic acids, polyelectrolytes) and charged surfaces govern many natural and industrial processes. We investigate here the influence of an applied electric potential on the adsorption of charged polymers, and report the following significant result: the adsorption of certain amine side chain-containing polycations may become continuous, i.e., asymptotically linear (or nearly linear) in time over hours, upon the application of a modest anodic potential. Employing optical waveguide lightmode spectroscopy (OWLS) and an indium tin oxide (ITO) substrate, we show that asymptotic kinetics, and the adsorbed mass at the onset of the asymptotic regime, depend sensitively on polymer chemistry (in particular, side chain volume and charge location), increase with applied potential and ionic strength (conditions favoring a thicker initial layer), and are independent of bulk polymer concentration (suggesting postadsorption events to be rate limiting). X-ray photoelectron spectra reveal a suppressed polymer charge within layers formed via continuous adsorption, but no evidence of electrochemical reactions. We propose a mechanism based on polymer-polymer binding within the adsorbed layer, enabled by suppressed electrostatic repulsion and/or enhanced ionic correlations near the conducting surface, and stabilized by short-range attractive interactions. Continuous adsorption under an applied electric potential offers the possibility of nanoscale films of tailored polymer content realized in a single step.optical waveguide lightmode spectroscopy ͉ poly(L-lysine) ͉ protein adsorption ͉ indium tin oxide I nteractions between charged macromolecules and charged surfaces are ubiquitous in nature (e.g., protein-cell membrane) and are often exploited in technological applications. For example, weakly charged colloidal systems such as paints, inks, and waste water may be stabilized through an adsorbed layer of charged polymer (polyelectrolyte) (1, 2), and polyelectrolyte films containing functional entities (e.g., biomolecules, nanoparticles) may serve as sensors, separation membranes, and electrochemical components (3, 4). Adsorption is usually spontaneous, with electrostatic interactions naturally playing a key role. These interactions, and therefore the adsorption process itself, may be controlled through solution variables such as salt concentration and pH (5-12). However, there generally exists an upper limit to the extent of polyelectrolyte adsorption. The typical situation is for adsorption to be quite rapid (usually at a transport limited rate) and then to saturate, corresponding to the point where interfacial charge accumulation suppresses additional (net) adsorption (1). A clever way to avoid this limit is through the layer-by-layer (LbL) method, where a substrate is alternately exposed to solutions of oppositely charged polyelectrolytes (3, 13). Each exposure results in an increase in adsorbed mass and an overall interfacial charge reversal. The LbL method allows one t...

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Section: Discussionmentioning

confidence: 99%

Continuous polyelectrolyte adsorption under an applied electric potential

Ngankam

Tassel

2007

Proc. Natl. Acad. Sci. U.S.A.

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“…Interestingly, collagen type I molecules adsrob strongly on the Au surface at moderate positive and negative charges accumulated on the electrode surface. By conrast, many globular proteins adsorb strongest on metal surfaces at a potential corresponding to the potential of zero charge [168]. This unusual adsorption behavior of collagen is due to its uniqueness among proteins structure.…”

Section: Application Of In Situ Pm Irras For the Determination Of Thementioning

confidence: 99%

Application of Polarization Modulation Infrared Reflection Absorption Spectrosocpy Under Electrochemical Control for Structural Studies of Biomimetic Assemblies

Brand

2015

Zeitschrift Für Physikalische Chemie

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An ideal bioanalytical method would allow carrying out sensitive, selective, reproducible, fast, and in situ chemical measurements of the composition, structure and function of complex biological systems. Physical chemistry possesses advanced structure analyzing techniques which are suitable to solve, at a sub-molecular level, the structure of biomolecules. However, the prerequisite of the presence of the electrolyte solution limits the number of applicable structure analyzing techniques. Infrared spectroscopy is one of the most powerful analytical techniques used to identify the structure of biomolecules, monitor structural changes under various experimental environments and physical states. In addition, infrared reflection absorption spectroscopy (IRRAS) has been successfully applied to study supramolecular films at the solid|liquid interface. Assemblies of biomolecules belong to a particularly demanding because they bring specific for the maintenance of their functions experimental requirements which have to be taken into account planning in situ spectroelectrochemical experiments. In this paper potnential of in situ IRRAS under electrochemical control for studies of structural changes in assemblies of biomolecules such as lipid bilayers and protein films is described. Studies of different classes of biomolecules bring certain experimetnal conditions concerning the electrolyte composition, pH value, temperature or chemical nature of the solid support, which have to be fulfilled. Obviously, these conditons may significantly restrict the applicability of the in situ PM IRRAS. The selection of the solid substrate with required optical and electrical properties, the optical window and the electrolyte composition have to be adapted to the needs of biomolecules. Adjustement of experimetnal conditions as well as possibilites of the enlargement of the in situ PM IRRAS for studies of biomimetic assemblies is reviewed in this paper. Furthermore, experimetnal resutls reporting potenial driven changes in models of cell membranes and protein films are reviewed. Pioneering studies aiminig at the determination of structural changes in lipid membranes exposed to physiological electric fields and interacting simultaneously with protiens are described.

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“…Their respecamount adsorbed as a function of time, including ellipsome-tive F(ab) 2 and Fc fragments were obtained by papain ditry (10,11,12), Fourier transform infrared (13,14), total gestion under nonreducing conditions as described preinternal reflection fluorescence (15,16), g-photon spectros-viously (22). Some characteristics of the IgG's and their copy (17), and streaming potential measurements (18).…”

Section: Ismentioning

confidence: 99%