Stabilizing Effects of Various Polyelectrolyte Multilayer Films on the Structure of Adsorbed/Embedded Fibrinogen Molecules:  An ATR−FTIR Study

Schwinté, Pascale; Voegel, Jean‐Claude; Picart, Catherine; Haïkel, Youssef; Schaaf, Pierre; Szalontai, Balázs

doi:10.1021/jp0123031

Cited by 186 publications

(246 citation statements)

References 42 publications

(63 reference statements)

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“…The amide IЈ band of the casein lost upon the first CaP treatment (Fig. 3, Cap-I) was similar to the amide IЈ bands of the adsorbing caseins, in agreement with our earlier finding that polyelectrolyte film stabilized the structure of the adsorbed proteins (12). In contrast, the amide IЈ bands of the caseins desorbing upon the second CaP and Ca 2ϩ treatments (Fig.…”

Section: Effect Of Calcium Phosphate Nanoclusters On Caseinsupporting

confidence: 90%

“…For the FTIR experiments, polyelectrolyte films were built up with the layer-by-layer method by adsorbing the polyelectrolytes onto the surface of the ATR crystal from solutions circulated by a peristaltic pump as in Ref. 12. Extensive washing periods separated the administrations of the differently charged polyelectrolytes.…”

Section: Methodsmentioning

confidence: 99%

“…We have shown earlier that proteins and proteolipid membranes can adsorb onto such polyelectrolyte films, and their native secondary structure is little affected (11). In addition, once a protein has been adsorbed, its secondary structure is stabilized/fixed by the interaction with the polyelectrolyte film (12,13).…”

mentioning

confidence: 98%

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Casein Aggregates Built Step-by-Step on Charged Polyelectrolyte Film Surfaces Are Calcium Phosphate-cemented

Nagy

Pilbat

Groma

et al. 2010

Journal of Biological Chemistry

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The possible mechanism of casein aggregation and micelle buildup was studied in a new approach by letting ␣-casein adsorb from low concentration (0.1 mg⅐ml ؊1 ) solutions onto the charged surfaces of polyelectrolyte films. It was found that ␣-casein could adsorb onto both positively and negatively charged surfaces. However, only when its negative phosphoseryl clusters remained free, i.e. when it adsorbed onto a negative surface, could calcium phosphate (CaP) nanoclusters bind to the casein molecules. Once the CaP clusters were in place, step-by-step building of multilayered casein architectures became possible. The presence of CaP was essential; neither Ca 2؉ nor phosphate could alone facilitate casein aggregation. Thus, it seems that CaP is the organizing motive in the casein micelle formation. Atomic force microscopy revealed that even a single adsorbed casein layer was composed of very small (in the range of tens of nanometers) spherical forms. The stiffness of the adsorbed casein layer largely increased in the presence of CaP. On this basis, we can imagine that casein micelles emerge according to the following scheme. The amphipathic casein monomers aggregate into oligomers via hydrophobic interactions even in the absence of CaP. Full scale, CaP-carrying micelles could materialize by interlocking these casein oligomers with CaP nanoclusters. Such a mechanism would not contradict former experimental results and could offer a synthesis between the submicelle and the block copolymer models of casein micelles.In milk, casein micelles serve the transport of calcium phosphate (CaP), 2 the essential bone-building component, which is insoluble in water already at feeble concentrations. Caseins, a family of phosphoproteins, are the largest protein component of milk. They can be classified into two groups according to their calcium sensitivity: in bovine milk, ␣ s1 -, ␣ s2 -, and ␤-caseins precipitate in the presence of calcium; -casein remains in solution. The calcium-sensitive caseins are highly phosphorylated, and their phosphoseryl residues are organized into 2-, 3-, or 4-unit clusters. Although the phosphoseryl clusters are highly conserved, other parts of the caseins exhibit high mutational rates; however, these mutations tend to preserve the hydrophobic or hydrophilic character of the mutated amino acids (1). This may indicate that the amphipathic character must be important for caseins. Indeed, it turned out being the case when models were proposed to explain the existence and behavior of the casein micelles.For the micelle structure, several models have been proposed over the years, which are excellently compared and discussed in recent reviews (2-4). Here, we mention only the two persisting models. One of them says that micelles are created in two steps as follows: first, submicelles are formed, and these submicelles are then organized to the final micelles; the second model says that the micelles are built by continuous incorporation of single molecules (block copolymers (5)), whose aggregation is governed ...

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Section: Effect Of Calcium Phosphate Nanoclusters On Caseinsupporting

confidence: 90%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Casein Aggregates Built Step-by-Step on Charged Polyelectrolyte Film Surfaces Are Calcium Phosphate-cemented

Nagy

Pilbat

Groma

et al. 2010

Journal of Biological Chemistry

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“…The analysis of the amide I modes of PM IRRA spectra of albumin adsorbed on the stainless steel surface show that the increase in the surface concentration of the adsorbed protein leads to a gradual loss of the helical structure and unfolding of the adsorbed protein [162]. Fibrinogen is a large dimer protein composed of two hydrophobic outer domains (D) which are bound to a central hydrophilic domain (E) via two coiled -helix coils [167]. In a native fibrinogen the content of -helix secondary structure is close to 30-37% and -sheet to 21-30%.…”

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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“…The analysis of the infrared spectra was carried out using the SPSERV© software. 29 The FTIR experiments were performed in deuterated 25mM TRIS buffer. The spectra of the precursor PEI-(PSS-PAH) 4 multilayer film deposited onto the ZnSe crystal was first recorded.…”

Section: Fourier Transform Infrared Spectroscopy (Ftir)mentioning

confidence: 99%

Polyelectrolyte-Mediated Adsorption of Amelogenin Monomers and Nanospheres Forming Mono- or Multilayers

et al. 2007

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We have applied optical waveguide lightmode spectroscopy combined with streaming potential measurements and Fourier transformed infrared spectroscopy to investigate adsorption of amelogenin nanospheres onto polyelectrolytes. The long term objective was to better understand the chemical nature of these assemblies and to gain further insight into the molecular mechanisms involved during self-assembly. It was found that monolayers of monomers and negatively charged nanospheres of a recombinant amelogenin (rM179) irreversibly adsorbed onto a positively charged polyelectrolyte multilayer films. Based on measurements performed at different temperatures it was demonstrated that intermolecular interactions for the formation of nanospheres were not affected by their adsorption onto polyelectrolytes. Consecutive adsorption of nanospheres resulting in the formation of multilayer structures was possible by using cationic poly(L-lysine) as mediators. NAcetyl-D-Glucosamine (GlcNac) did not disturb the nanosphere-assembled protein's structure and it only affected the adsorption of monomeric amelogenin. Infrared spectroscopy of adsorbed amelogenin revealed conformational differences between the monomeric and assembled forms of rM179. While there was a considerable amount of α-helices in the monomers, β-turn and β-sheet structures dominated the assembled proteins. Our work constitutes the first report on a structurally controlled in-vitro buildup of an rM179 nanosphere monolayer-based matrix. Our data support the notion that amelogenin self-assembly is mostly driven by hydrophobic interactions and that amelogenin/PEM interactions are dominated by electrostatic forces. We suggest that similar forces can govern amelogenin interactions with non-amelogenins or the mineral phase during enamel biomineralization.

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Stabilizing Effects of Various Polyelectrolyte Multilayer Films on the Structure of Adsorbed/Embedded Fibrinogen Molecules: An ATR−FTIR Study

Cited by 186 publications

References 42 publications

Casein Aggregates Built Step-by-Step on Charged Polyelectrolyte Film Surfaces Are Calcium Phosphate-cemented

Casein Aggregates Built Step-by-Step on Charged Polyelectrolyte Film Surfaces Are Calcium Phosphate-cemented

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

Polyelectrolyte-Mediated Adsorption of Amelogenin Monomers and Nanospheres Forming Mono- or Multilayers

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