Charge determination of proteins with polyelectrolyte titration.

Horn, D.; Heuck, C C

doi:10.1016/s0021-9258(18)33037-0

Cited by 73 publications

(28 citation statements)

References 33 publications

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“…The indication of a 1:1 complex between polycation and polyanion by a dye responding to an excess of one polyion was first described 1952 . We use a phototitrator which was a gift by BASF and described by Horn . A PSS solution was added by an autotitrator to a sample of PDADMAC which was diluted with ∼100 mL of water.…”

Section: Methodsmentioning

confidence: 99%

Influence of Architecture on the Interaction of Negatively Charged Multisensitive Poly(N-isopropylacrylamide)-co-Methacrylic Acid Microgels with Oppositely Charged Polyelectrolyte: Absorption vs Adsorption

2010

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Two sets of core-shell microgels composed of temperature-sensitive poly(N-isopropylacrylamide) (PNiPAM) with different spatial distribution of pH-sensitive methacrylic acid (MAA) groups were prepared. The cores consist of either PNiPAM (neutral core; nc) or PNiPAM-co-MAA (charged core; cc). A charged shell existing of PNiPAM-co-MAA was added to the neutral core (yielding neutral core-charged shell; nccs), on the charged core, on the other hand, a neutral shell of PNiPAM was added (charged core-neutral shell; ccns). Complexes of these microgels with positively charged poly(diallyldimethylammonium chloride) (PDADMAC) of different molar masses were prepared. The amount of bound polyelectrolyte was quantified, and the microgel-polyelectrolyte complexes were characterized with respect to electrophoretic mobility and hydrodynamic radius. The penetration of polyelectrolyte into the microgel was also monitored by means of lifetime analysis of a fluorescent dye covalently bound to poly(L-lysine) providing information on the probe's local environment. The architecture of the microgel has a significant influence on the interaction with oppositely charged polyelectrolyte. Complexes with microgel with the charged shell tend to flocculate at charge ratios of 1 and are thus similar to polyelectrolyte complexes with rigid colloidal particles. Complexes with microgels that consist of a charged core and a neutral shell show very different properties: They are still temperature sensitive and reveal an influence of the polyelectrolyte's chain length. Low molecular weight PDADMAC can penetrate through the neutral shell into the charged core, and thus nearly no charge reversal occurs. The high-MW polyelectrolyte does not penetrate fully and leads to charge reversal. The results demonstrate that microgels are able to absorb or adsorb polyelectrolytes depending on the polyelectrolyte's chain length and the microgels architecture. Complexes with different surface properties and different colloidal stability can be prepared, and polyelectrolytes can be encapsulated in the microgel core. Thus, multisensitive core-shell microgels combine permeability and compartmentalization on a nanometer length scale and provide unique opportunities for applications in controlled uptake and release.

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Section: Methodsmentioning

confidence: 99%

Influence of Architecture on the Interaction of Negatively Charged Multisensitive Poly(N-isopropylacrylamide)-co-Methacrylic Acid Microgels with Oppositely Charged Polyelectrolyte: Absorption vs Adsorption

2010

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“…Numbers are given as pK IV in Table 1. These modifications are based on recommendations by Horn and Heuck (1983) and Laussac and Sarkar (1985). However, as at pH ≈ 7 the dissociation of the carboxylic group in the residue of glutamic acid is nearly complete and the protonation of the…”

Section: Methodsmentioning

confidence: 99%

Partitioning of Some Amino Acids and Low Molecular Mass Peptides in Aqueous Two-Phase Systems of Poly(ethylene glycol) and Dextran in the Presence of Small Amounts of K₂HPO₄/KH₂PO₄-Buffer at 293 K: Experimental Results and Correlation

et al. 1997

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Buffered aqueous two-phase systems are effective extraction systems for separating amphoteric hydrocarbons like, for example, polypeptides from aqueous phases. The design and basic engineering of such processes require the knowledge of the liquid-liquid equilibrium. Methods to calculate and predict the liquid-liquid phase equilibrium in those systems can only be developed when a large data base is available. The present contribution is aimed at that goal by presenting experimental results for the partitioning of small amounts (≈0.001 g/g solution) of model substancessamino acids glycine, L-glutamic acid, L-phenylalanine, and L-lysine as well as dipeptides and some higher, but still low, molecular peptides of those single amino acidssin aqueous two-phase systems of dextran and poly(ethylene glycol) in the presence of small amounts (about 0.05 mol/kg) of K 2 HPO 4 /KH 2 PO 4 -buffer at about 293 K. A group contribution model for the excess Gibbs energy is used to correlate/predict that liquid-liquid phase equilibrium.

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“…This quenching is also observed in the presence of high amounts of the non-polymeric D-glucosamine. Indeed, the weaker interaction with glucosamine can be explained by binding cooperativity in electrostatic interactions [44] and cooperativity of stacking interaction that requires a minimal critical chain length, as shown in other PEL -dye interactions [40,42].…”

Section: Final Remarksmentioning

confidence: 98%

New insights into the nature of the Cibacron brilliant red 3B-A – Chitosan interaction

Hoffmann

Werner

Moreno‐Villoslada

et al. 2016

Pure and Applied Chemistry

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Cibacron brilliant red 3B-A (CBR) has been introduced to determine chitosan (CS) concentrations in solution, and several studies applied it to measure chitosan content in pharmaceutical formulations. So far, studies have relied on the absorbance band shift to 570 nm to determine the extent of the CBR – CS interaction. In this study, we show that CBR forms micro- to nanometer sized aggregates with CS, depending on their charge ratio and that other photophysical changes in CBR are induced by this interaction. We found that, besides the bathochromic band shift, aggregation induces emission at 600 nm and emission quenching at 360 nm. We compared changes CS induced in absorbance and fluorescence emission of CBR with the CS monomer glucosamine and poly(allylamine) hydrochloride, which both contain amino groups, and found that similar but less intense photophysical changes also occur. Furthermore, CS-induced circular dichroism in CBR suggests a twisted, chiral structure of these aggregates that should match with the previously published in silico simulations of the structure of CS in solution. The low linear charge density of CS and its chiral conformation are considered responsible for the enhanced photophysical response of CBR interacting with the polycation.

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Charge determination of proteins with polyelectrolyte titration.

Cited by 73 publications

References 33 publications

Influence of Architecture on the Interaction of Negatively Charged Multisensitive Poly(N-isopropylacrylamide)-co-Methacrylic Acid Microgels with Oppositely Charged Polyelectrolyte: Absorption vs Adsorption

Influence of Architecture on the Interaction of Negatively Charged Multisensitive Poly(N-isopropylacrylamide)-co-Methacrylic Acid Microgels with Oppositely Charged Polyelectrolyte: Absorption vs Adsorption

Partitioning of Some Amino Acids and Low Molecular Mass Peptides in Aqueous Two-Phase Systems of Poly(ethylene glycol) and Dextran in the Presence of Small Amounts of K₂HPO₄/KH₂PO₄-Buffer at 293 K: Experimental Results and Correlation

New insights into the nature of the Cibacron brilliant red 3B-A – Chitosan interaction

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Charge determination of proteins with polyelectrolyte titration.

Cited by 73 publications

References 33 publications

Influence of Architecture on the Interaction of Negatively Charged Multisensitive Poly(N-isopropylacrylamide)-co-Methacrylic Acid Microgels with Oppositely Charged Polyelectrolyte: Absorption vs Adsorption

Influence of Architecture on the Interaction of Negatively Charged Multisensitive Poly(N-isopropylacrylamide)-co-Methacrylic Acid Microgels with Oppositely Charged Polyelectrolyte: Absorption vs Adsorption

Partitioning of Some Amino Acids and Low Molecular Mass Peptides in Aqueous Two-Phase Systems of Poly(ethylene glycol) and Dextran in the Presence of Small Amounts of K2HPO4/KH2PO4-Buffer at 293 K: Experimental Results and Correlation

New insights into the nature of the Cibacron brilliant red 3B-A – Chitosan interaction

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Product

Resources

About

Partitioning of Some Amino Acids and Low Molecular Mass Peptides in Aqueous Two-Phase Systems of Poly(ethylene glycol) and Dextran in the Presence of Small Amounts of K₂HPO₄/KH₂PO₄-Buffer at 293 K: Experimental Results and Correlation