Application of Congo red dye as a molecular probe to investigate the kinetics and thermodynamics of the formation processes of arachin and conarachin nanocomplexes

Jaqueline de Paula Rezende; Hauster Maximiler Campos De Paula; Talma Duarte Freitas; Yara Luiza Coelho; Luis Henrique Mendes Da Silva; Ana Clarissa Dos Santos Pires

doi:10.1016/j.foodchem.2022.132485

Application of Congo red dye as a molecular probe to investigate the kinetics and thermodynamics of the formation processes of arachin and conarachin nanocomplexes

Food Chem. 2022 Aug 1:384:132485. doi: 10.1016/j.foodchem.2022.132485. Epub 2022 Feb 16.

Authors

Jaqueline de Paula Rezende¹, Hauster Maximiler Campos De Paula², Talma Duarte Freitas¹, Yara Luiza Coelho², Luis Henrique Mendes Da Silva³, Ana Clarissa Dos Santos Pires⁴

Affiliations

¹ Applied Molecular Thermodynamics Group (THERMA), Department of Food Technology, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36570900 Viçosa, MG, Brazil.
² Colloidal and Macromolecular Green Chemistry Group (QUIVECOM), Department of Chemistry, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36570900 Viçosa, MG, Brazil.
³ Colloidal and Macromolecular Green Chemistry Group (QUIVECOM), Department of Chemistry, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36570900 Viçosa, MG, Brazil. Electronic address: luhen@ufv.br.
⁴ Applied Molecular Thermodynamics Group (THERMA), Department of Food Technology, Federal University of Viçosa, Av. P. H. Rolfs s/n, 36570900 Viçosa, MG, Brazil. Electronic address: ana.pires@ufv.br.

PMID: 35219985
DOI: 10.1016/j.foodchem.2022.132485

Abstract

The thermodynamics and kinetics of arachin-Congo red (ARA-CR) and conarachin-Congo red (CON-CR) interactions were studied using surface plasmon resonance. KCl led to a reduction of up to 55% in the values of the associated kinetic constants, but it had less influence on the dissociation rates (less than 12%). The change in ionic strength had little effect on the thermodynamic stability of the complexes, but it did reduce their affinities ( [Formula: see text] from 3.52 to 2.44 × 10³ M^-1 and [Formula: see text] from 15.1 to 12.5 × 10³ M^-1). The shielding of the electrical double layer favored ARA-CR hydrophilic interactions ( [Formula: see text] decreased from -30.60 to -42.98 kJ mol^-1). On the other hand, hydrophobic interactions came to dominate during the formation of [CON-CR]⁰ ( [Formula: see text] increased from -11.21 to 28.34 kJ mol^-1 and [Formula: see text] increased from 12.64 to 51.73 kJ.mol^-1). The data presented here improve our understanding of plant-based protein nanocarriers of small bioactive molecules.

Keywords: Hydrophobic/hydrophilic balance; Nanocarriers; Plant-based protein; Surface plasmon resonance; Transition complex.

MeSH terms

Congo Red* / chemistry
Kinetics
Molecular Probes*
Plant Proteins
Thermodynamics

Substances

Molecular Probes
Plant Proteins
Arachin
Congo Red