Protein-sugar interactions: Environmental effect on the fluorescence of O-(4-methylumbelliferyl)-glycosides

• Published in: Biochemical and biophysical research communications Vol. 110; no. 3; pp. 926 - 933
• Main Authors: Midoux, P., Delmotte, F., Grivet, J.Ph, Monsigny, M.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 10.02.1983; Elsevier
• Subjects: Amino Acids; Glycosides; Hymecromone - analogs & derivatives; Kinetics; Lectins; Life Sciences; Solvents; Spectrometry, Fluorescence; Structure-Activity Relationship; Umbelliferones; Wheat Germ Agglutinins; WGA; GlcNAc; MUF
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/0006-291X(83)91051-3

We have investigated the effect of 12 solvents and several amino acids on the fluorescence of O-(4-methylumbelliferyl)-glycosides. We showed that: i) the fluorescence quenching is not related to the dielectric constant of the solvents: the fluorescence intensity was maximal in water (d=80) and in acetic acid (d=6.2) and was at least ten times lower in acetone (d=21) and in dioxane (d=2.2); ii) the fluorescence of O-(4-methylumbelliferyl)- N-acetyl-β-glucosaminide is not quenched in the presence of various amino acids including arginine, asparagine, aspartate, histidine, leucine, phenylalanine and proline; iii) the fluorescence of O-(4-methylumbelliferyl)-glycoside is quenched by sulfur, phenol and indole amino acids or derivatives containing sulfur, phenol or indole groups. The changes in fluorescence intensities of O-(4-methylumbelliferyl)-glycosides upon binding to concanavalin A, wheat germ agglutinin and lysozyme are discussed with regard to the amino acid content of their binding sites.