Testing molecular interactions is an ubiquitous need in modern biology and molecular medicine. Here, we present a qualitative and quantitative method rooted in the basic properties of the scattering of light, enabling detailed measurement of ligand-receptor interactions occurring on the surface of colloids. The key factor is the use of receptor-coated nanospheres matched in refractive index with water and therefore optically undetectable ("phantom") when not involved in adhesion processes. At the occurrence of ligand binding at the receptor sites, optically unmatched material adsorbs on the nanoparticle surface, giving rise to an increment in their scattering cross section up to a maximum corresponding to saturated binding sites. The analysis of the scattering growth pattern enables extracting the binding affinity. This label-free method has been assessed through the determination of the binding constant of the antibiotic vancomycin with the tripeptide L-Lys-D-Ala-D-Ala and of the vancomycin dimerization constant. We shed light on the role of chelate effect and molecular hindrance in the activity of this glycopeptide.

Ghetta, A., Prosperi, D., Mantegazza, F., Panza, L., Riva, S., Bellini, T. (2005). Light scattered by model phantom bacteria reveals molecular interactions at their surface. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 102(44), 15866-15870 [10.1073/pnas.0505877102].

Light scattered by model phantom bacteria reveals molecular interactions at their surface

PROSPERI, DAVIDE;MANTEGAZZA, FRANCESCO;
2005

Abstract

Testing molecular interactions is an ubiquitous need in modern biology and molecular medicine. Here, we present a qualitative and quantitative method rooted in the basic properties of the scattering of light, enabling detailed measurement of ligand-receptor interactions occurring on the surface of colloids. The key factor is the use of receptor-coated nanospheres matched in refractive index with water and therefore optically undetectable ("phantom") when not involved in adhesion processes. At the occurrence of ligand binding at the receptor sites, optically unmatched material adsorbs on the nanoparticle surface, giving rise to an increment in their scattering cross section up to a maximum corresponding to saturated binding sites. The analysis of the scattering growth pattern enables extracting the binding affinity. This label-free method has been assessed through the determination of the binding constant of the antibiotic vancomycin with the tripeptide L-Lys-D-Ala-D-Ala and of the vancomycin dimerization constant. We shed light on the role of chelate effect and molecular hindrance in the activity of this glycopeptide.
Articolo in rivista - Articolo scientifico
light scattering
English
15866
15870
Ghetta, A., Prosperi, D., Mantegazza, F., Panza, L., Riva, S., Bellini, T. (2005). Light scattered by model phantom bacteria reveals molecular interactions at their surface. PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 102(44), 15866-15870 [10.1073/pnas.0505877102].
Ghetta, A; Prosperi, D; Mantegazza, F; Panza, L; Riva, S; Bellini, T
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/1329
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