Cetyltrimethylammonium chloride (CTAC) effect on the thermal stability of oxy-HbGp: Dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) studies

Carvalho, José Wilson Pires; Carvalho, Francisco Adriano de Oliveira; Batista, Tatiana; Santiago, Patrícia S.; Tabak, Marcel

doi:10.1016/j.colsurfb.2014.03.021

Cited by 20 publications

(21 citation statements)

References 27 publications

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“…However, the increase of the count rate intensity observed from 518C for oxy-HbGp without DTAB, and from 43 and 368C, in the presence of DTAB 0.5 and 1.0 mmol/L, respectively, is associated to the denaturation and aggregation of hemoglobin. Our DLS and DSC data corroborate the recent work on the CTAC-HbGp interactions, reported by Carvalho et al (2014). CTAC-HbGp interactions lead to a significant decrease of the hemoglobin thermal stability, and to formation of larger aggregates, at pH 5.0 and 7.0.…”

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 94%

“…For DTAB 0.0 mmol/L (Figure 7A), the hemoglobin remains stable up to 518C with hydrodynamic diameter around 28 nm which is in good agreement with DLS results, at pH 7.0, presented by Carvalho et al (2014). 31 At higher temperature, the protein aggregation/denaturation occurs, reaching a hydrodynamic diameter of around 330 nm, at 708C. In the presence of DTAB 0.5 and 1.0 mmol/L, the protein denaturation and aggregation starts at 43 and 368C, respectively (Figure7A).…”

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 92%

“…It is also observed a partial oligomeric dissociation, with and without CTAC, before denaturation and aggregation with increase of temperature at both pH values. 31 In general, the recent studies reported on the cationic surfactant-HbGp mixtures, such as DTAB-ANS-HbGp 22 and CTAC-HbGp 31 systems, regarding the HbGp oligomeric dissociation, denaturation and/or aggregation processes, at different temperatures and pH values, are also consistent with the structural changes of oxy-HbGp-DTAB system presented here. For example, the increase of temperature induces a partial hemoglobin oligomeric dissociation followed by denaturation and aggregation, both for CTAC 31 and DTAB, as monitored by …”

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 88%

“…The hemoglobin shows hydrodynamic diameter of around 28 nm in the absence and presence of DTAB at 258C. For DTAB 0.0 mmol/L (Figure 7A), the hemoglobin remains stable up to 518C with hydrodynamic diameter around 28 nm which is in good agreement with DLS results, at pH 7.0, presented by Carvalho et al (2014). 31 At higher temperature, the protein aggregation/denaturation occurs, reaching a hydrodynamic diameter of around 330 nm, at 708C.…”

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 85%

“…Furthermore, the hemoglobin undergoes a partial oligomeric dissociation with and without CTAC and upon the increase of the temperature, before denaturation and aggregation, also at both pH values. 31 Thus, the asymmetry of the endothermic peak presented in DSC curves for DTAB-hemoglobin interactions, may be associated to the simultaneous occurrence of dissociation, denaturation and aggregation mechanisms. Probably, dissociated species, as dodecamer and tetramer, together with native HbGp are present in solution, and the aggregation process can be attributed to the interaction between whole hemoglobin molecules with neutralized surface charges promoted by DTAB addition.…”

Section: Dtab-oxy-hbgp Interaction By Calorimetry 205mentioning

confidence: 99%

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Interaction of cationic dodecyl‐trimethyl‐ammonium bromide with oxy‐HbGp by isothermal titration and differential scanning calorimetric studies: Effect of proximity of isoelectric point

Alves

Carvalho

et al. 2016

Biopolymers

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In this work, isothermal titration and differential scanning calorimetric methods, in combination with pyrene fluorescence emission and dynamic light scattering have been used to investigate the interaction of dodecyltrimethylammonium bromide (DTAB) with the giant extracellular Glossoscolex paulistus hemoglobin (HbGp) in the oxy-form, at pH values around the isoelectric point (pI ≈ 5.5). Our ITC results have shown that the interaction of DTAB with the hemoglobin is more intense at pH 7.0, with a smaller cac (critical aggregation concentration) value. The increase of protein concentration does not influence the cac value of the interaction, at both pH values. Therefore, the beginning of the DTAB-oxy-HbGp premicellar aggregates formation, in the cac region, is not affected by the increase of protein concentration. HSDSC studies show higher Tm values at pH 5.0, in the absence and presence of DTAB, when compared with pH 7.0. Furthermore, at pH 7.0, an aggregation process is observed with DTAB in the range from 0.75 to 1.5 mmol/L, noticed by the exothermic peak, and similar to that observed for pure oxy-HbGp, at pH 5.0, and in the presence of DTAB. DLS melting curves show a decrease on the hemoglobin thermal stability for the oxy-HbGp-DTAB mixtures and formation of larger aggregates, at pH 7.0. Our present data, together with previous results, support the observation that the protein structural changes, at pH 7.0, occur at smaller DTAB concentrations, as compared with pH 5.0, due to the acidic pI of protein that favors the oxy-HbGp-cationic surfactant interaction at neutral pH.

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Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 94%

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 92%

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 88%

Section: Dtab-oxy-hbgp Interaction By Calorimetry 207supporting

confidence: 85%

Section: Dtab-oxy-hbgp Interaction By Calorimetry 205mentioning

confidence: 99%

See 3 more Smart Citations

Interaction of cationic dodecyl‐trimethyl‐ammonium bromide with oxy‐HbGp by isothermal titration and differential scanning calorimetric studies: Effect of proximity of isoelectric point

Alves

Carvalho

et al. 2016

Biopolymers

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Confining the Sol‐Gel Reaction at the Water/Oil Interface: Creating Compartmentalized Enzymatic Nano‐Organelles for Artificial Cells

et al. 2023

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Living organisms compartmentalize their catalytic reactions in membranes for increased efficiency and selectivity. To mimic the organelles of eukaryotic cells, we develop a mild approach for in situ encapsulating enzymes in aqueous-core silica nanocapsules. In order to confine the sol-gel reaction at the water/oil interface of miniemulsion, we introduce an aminosilane to the silica precursors, which serves as both catalyst and an amphiphilic anchor that electrostatically assembles with negatively charged hydrolyzed alkoxysilanes at the interface. The semi-permeable shell protects enzymes from proteolytic attack, and allows the transport of reactants and products. The enzyme-carrying nanocapsules, as synthetic nano-organelles, are able to perform cascade reactions when enveloped in a polymer vesicle, mimicking the hierarchically compartmentalized reactions in eukaryotic cells. This in situ encapsulation approach provides a versatile platform for the delivery of biomacromolecules.

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Confining the Sol‐Gel Reaction at the Water/Oil Interface: Creating Compartmentalized Enzymatic Nano‐Organelles for Artificial Cells

et al. 2023

View full text Add to dashboard Cite

Living organisms compartmentalize their catalytic reactions in membranes for increased efficiency and selectivity. To mimic the organelles of eukaryotic cells, we develop a mild approach for in situ encapsulating enzymes in aqueous‐core silica nanocapsules. In order to confine the sol‐gel reaction at the water/oil interface of miniemulsion, we introduce an aminosilane to the silica precursors, which serves as both catalyst and an amphiphilic anchor that electrostatically assembles with negatively charged hydrolyzed alkoxysilanes at the interface. The semi‐permeable shell protects enzymes from proteolytic attack, and allows the transport of reactants and products. The enzyme‐carrying nanocapsules, as synthetic nano‐organelles, are able to perform cascade reactions when enveloped in a polymer vesicle, mimicking the hierarchically compartmentalized reactions in eukaryotic cells. This in situ encapsulation approach provides a versatile platform for the delivery of biomacromolecules.

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Cetyltrimethylammonium chloride (CTAC) effect on the thermal stability of oxy-HbGp: Dynamic light scattering (DLS) and small angle X-ray scattering (SAXS) studies

Cited by 20 publications

References 27 publications

Interaction of cationic dodecyl‐trimethyl‐ammonium bromide with oxy‐HbGp by isothermal titration and differential scanning calorimetric studies: Effect of proximity of isoelectric point

Interaction of cationic dodecyl‐trimethyl‐ammonium bromide with oxy‐HbGp by isothermal titration and differential scanning calorimetric studies: Effect of proximity of isoelectric point

Confining the Sol‐Gel Reaction at the Water/Oil Interface: Creating Compartmentalized Enzymatic Nano‐Organelles for Artificial Cells

Confining the Sol‐Gel Reaction at the Water/Oil Interface: Creating Compartmentalized Enzymatic Nano‐Organelles for Artificial Cells

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