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Bottom-up approach to explore alpha-amylase assisted membrane remodelling
Harshit Kumar1, Sayar Mandal1, Reena Yadav2
1Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Sector 81, Knowledge City, Manauli, SAS Nagar, Punjab 140306, India.
Chemistry and Physics of Lipids
|January 4, 2024
Summary
Malt alpha-amylase (AA) interacts with lipid membranes, altering their mechanical properties. This enzyme can increase membrane bending rigidity and induce spontaneous curvature, impacting membrane morphology and elasticity.
Area of Science:
- Biochemistry
- Biophysics
- Membrane Biophysics
Background:
- Soluble alpha-amylases are key enzymes in polysaccharide breakdown.
- Lipid membranes are fundamental biological structures with crucial mechanical properties.
- Understanding enzyme-membrane interactions is vital for cell biology and drug delivery.
Purpose of the Study:
- To investigate the interaction of malt alpha-amylase (AA) with lipid membranes.
- To quantify the effect of AA on the mechanical properties of lipid vesicles.
- To characterize the concentration-dependent influence of AA on membrane morphology and elasticity.
Main Methods:
- Utilized vesicle fluctuation spectroscopy for quantitative measurement of membrane bending rigidity.
- Employed Giant Unilamellar Vesicles (GUVs) composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC).
- Analyzed shape fluctuations of GUVs to determine mechanical parameters.
Main Results:
- Malt AA significantly increased the bending rigidity of POPC lipid vesicles at low concentrations (0.14 μM).
- Higher AA concentrations (≥ 1.5 μM) induced spontaneous curvature and morphological changes, forming outbuds.
- AA demonstrated a concentration-dependent stabilization of membrane curvature.
Conclusions:
- Malt alpha-amylase interacts with the outer leaflet of lipid bilayers, affecting membrane elasticity.
- The enzyme's concentration dictates its impact, from increasing rigidity to inducing curvature.
- These findings highlight the significant role of enzyme-membrane interactions in modulating membrane mechanics.
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