A11 -Transfer of biomolecules across biological membranes

Introduction

Surface Plasmon Resonance (SPR) is a common method to study biomolecular interactions. This Application Note describes the results from a study*, which shows how SPR can be used to study another very important biological process, namely transfer of biomolecules across biological membranes. melittin is a small peptide and the active substance in honey-bee venom. Its toxicity is manifested by the formation of melittin pores in the cellular membrane and the subsequent lysis of the cell. The measurements of sucrose uptake through the melittin pore, which are presented here, demonstrate a general and straight-forward method to quantify and to measure, in real-time, transfer of molecules across biological membranes#.

Injection of sucrose (or any other solute) changes the refractive index (RI) of the solution in the evanescent-field volume above the sensor surface, which is manifested as a shift in RU. Liposomes immobilized at the biosensor surface occupy a part of the evanescent-field volume, and therefore the shift in RU upon injection of sucrose in presence of liposomes is lowered. If the liposomes contain melittin pores, sucrose can enter the volume enclosed by the liposomes and the response from a sucrose injection will now correspond to the change in RI of the volume inside and outside the liposomes.

Full Application note

Published 2010-03-04, at 10:23.