Dissipative Microgravimetry to Study the Binding Dynamics of the Phospholipid Binding Protein Annexin A2 to Solid-supported Lipid Bilayers Using a Quartz Resonator

作者： Anna Livia L. Matos*1,3, David Grill*1,3, Sergej Kudruk1,3, Nicole Heitzig1,3, Hans-Joachim Galla2,3, Volker Gerke1,3, Ursula Rescher1,3 1Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation,University of Münster, 2Institute of Biochemistry,University of Münster, 3Cluster of Excellence 'Cells in Motion',University of Münster

简介：

Overview

This article presents a protocol for determining the binding affinities and interaction modes of annexin A2 with solid-supported bilayers. The method allows for real-time observation of protein interactions with lipid membranes.

Key Study Components

Area of Science

• Neuroscience
• Biochemistry
• Biophysics

Background

• Annexin A2 is a phospholipid-binding protein.
• Understanding its interactions with lipid membranes is crucial for cellular processes.
• The study focuses on calcium-dependent binding to negatively charged phospholipids.
• The method is label-free and allows for sensitive, quantitative measurements.

Purpose of Study

• To analyze the binding interactions of annexin A2 with solid-supported lipid bilayers.
• To provide a detailed experimental protocol for researchers.
• To demonstrate the applicability of the method to other complex systems.

Methods Used

• Preparation of solid-supported lipid bilayers (SLB).
• Use of quartz crystal microbalance to measure mass uptake and viscoelastic properties.
• Real-time monitoring of frequency and dissipation changes.
• Calcium ion chelation to study protein dissociation.

Main Results

• The binding of annexin A2 to lipids is calcium-dependent.
• Frequency shifts indicate mass changes upon protein binding.
• Stable bilayer structure is maintained during the interaction.
• Negative control experiments confirm specificity of binding.

Conclusions

• The protocol provides a quantitative description of membrane protein interactions.
• Real-time analysis allows for detailed insights into binding mechanisms.
• This method can be adapted for studying other protein-lipid interactions.

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