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Updated: Jun 15, 2026
10:49
Method to Visualize and Analyze Membrane Interacting Proteins by Transmission Electron Microscopy
Published on: March 5, 2017
HAMLET interacts with lipid membranes and perturbs their structure and integrity
Ann-Kristin Mossberg1, Maja Puchades, Øyvind Halskau
1Section of Microbiology, Immunology, and Glycobiology, Institute of Laboratory Medicine, Lund University, Lund, Sweden.
Plos One
|February 27, 2010
Summary
Human alpha-lactalbumin made lethal to tumor cells (HAMLET) binds to lipid membranes, increasing fluidity and disrupting integrity. This interaction, requiring both protein and fatty acid, may initiate tumor cell death.
Area of Science:
- Biochemistry
- Cell Biology
- Membrane Biophysics
Background:
- Cell membrane interactions involve lipid bilayers and embedded molecules like receptors.
- HAMLET, a complex of unfolded alpha-lactalbumin and oleic acid, is tumoricidal and internalized by tumor cells.
- This suggests HAMLET's interaction with membranes or receptors is crucial for its effect.
Purpose of the Study:
- To investigate HAMLET's interaction with artificial membranes.
- To determine if HAMLET alters membrane structure and integrity.
Main Methods:
- Surface plasmon resonance (SPR) to assess HAMLET binding affinity to lipid vesicles.
- Fluorescence imaging to observe HAMLET accumulation and membrane perturbation.
- Fluorophore leakage experiments to evaluate membrane integrity.
Main Results:
- HAMLET exhibited high-affinity binding to lipid vesicles with diverse compositions.
- HAMLET increased membrane fluidity and disrupted membrane integrity under physiological conditions.
- These effects were specific to the HAMLET complex, not native or mutant alpha-lactalbumin.
Conclusions:
- HAMLET engages membranes via a mechanism dependent on both protein and fatty acid.
- HAMLET binding alters membrane morphology and compromises integrity.
- Membrane perturbation by HAMLET is a potential initial step in tumor cell death induction.
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