Lysozyme gelation in mixtures of tetramethylurea with protic solvents: Use of solvatochromic indicators to probe medium microstructure and solute-solvent interactions

Marcelo A. da Silva, Omar A. El Seoud, Elizabeth P.G. Arêas

Research output: Contribution to journalArticlepeer-review

9 Citations (SciVal)

Abstract

This work investigated the relationship between the structure of binary mixtures of tetramethylurea and protic solvents and their capacity to induce lysozyme gelation. In order to get an insight into the mechanism of gel formation, the solvatochromic behavior of zwitterionic probes, employed as simple models for the protein, was investigated. We studied two probes of similar pKa's, but different hydrophobic character, namely 2,6-diphenyl-4-(2,4,6-triphenylpyridinium-1-yl) phenolate, RB, and 4-[2-(1-methylpyridinium-4-yl) ethenyl] phenolate, MC. The protic solvents used included water, 1-propanol and 2-n-butoxyethanol in the temperature range from 10 to 60 °C, and methanol, from 10 to 40 °C. In all cases, the dependence of the empirical solvent polarity parameter, ET, on mixture composition was non-ideal with negative deviation for TMU-water and positive deviation for TMU-organic solvent. For all binary mixtures, the deviation from linearity decreased as a function of increasing the temperature. In TMU/alcohol, the effect became more pronounced with increasing alcohol hydrophobicity.

Original languageEnglish
Pages (from-to)51-60
Number of pages10
JournalJournal of Molecular Structure
Volume841
Issue number1-3
Early online date24 Jan 2007
DOIs
Publication statusPublished - 30 Sep 2007

Keywords

  • Binary mixtures
  • Micropolarity
  • Protein gelation
  • Rheology
  • Solvatochromic probes
  • Tetramethylurea

ASJC Scopus subject areas

  • Analytical Chemistry
  • Spectroscopy
  • Organic Chemistry
  • Inorganic Chemistry

Fingerprint

Dive into the research topics of 'Lysozyme gelation in mixtures of tetramethylurea with protic solvents: Use of solvatochromic indicators to probe medium microstructure and solute-solvent interactions'. Together they form a unique fingerprint.

Cite this