Biology subjects

Kudawla, R.

Publications and source records attributed to Kudawla, R..

3 recordsLinked to original sources

bioRxiv2026

Evolution of Vesicle Shape Parameters Based on A Deep-Learning Based Image Analysis Framework Over Extended Time Periods

A precise analysis of shape instabilities in cell-sized membrane compartments requires thorough quantification of the shape dynamics of individual components over extended periods. Herein, we have used phase-contrast microscopy to image giant unilamellar membrane vesicles (GUVs), which are widely used as model systems for cellular structures. GUVs were prepared in the fluid lamellar phase of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine with and without cholesterol dissolved within a potato starch solution. The morphological changes and budding dynamics of individual GUVs with different chemical compositions were quantified using a deep-learning based image analysis framework over extended time periods, by using phase-contrast micrographs as input data. This automated framework integrates contour-based detection of the mother vesicle with precise segmentation of daughter compartments, thereby enabling explicit identification and tracking of mother and daughter vesicles at high temporal resolution. These findings further facilitate the measurement of the temporal evolution of vesicle morphometrics including area, and local membrane curvature during budding, that can be used as an input to develop computational models aimed at elucidating curvature-driven membrane remodeling in complex soft materials.

biophysics↗

bioRxiv2026

A Saliva-Inspired Model of Enzymatic Starch Hydrolysis by Alpha Amylase

We demonstrate that the enzymatic activity of alpha-amylase (AA) can serve as an effective physicochemical trigger for membrane remodeling in giant unilamellar vesicles (GUVs). This work provides insight into how primitive protocellular reactions directly translate into the membrane's mechanical responses. Analysis of the potato starch utilized in this work is composed of ~26\% amylose and ~75\% amylopectin. Quantitative DNS analysis revealed time- and concentration-dependent accumulation of reducing sugars during starch degradation by AA. The HPLC-RID chromatograms demonstrated the synthesis of glucose, maltose, maltotriose, maltotetraose, maltopentaose, maltohexaose, and maltoheptaose, with maltose and maltotriose as the major products. The accumulation of these soluble hydrolysis products gradually increases the osmolarity of the extracellular medium surrounding the vesicles, leading to osmotic asymmetry across the membrane. This biochemical framework provides a quantitative basis for understanding membrane deformation, curvature generation, vesicle deflation, and budding. In addition to the specific starch--$\alpha$-amylase system studied here, our work uncovers a general mechanism by which external biochemical reactions control membrane shape transformations via osmotic coupling. Such enzyme-driven remodeling offers a simple yet powerful strategy for inducing dynamic structural changes in artificial cells. It may provide insight into primitive protocellular processes in which metabolic activity and membrane mechanics were inherently coupled.

biophysics↗

bioRxiv2024

Shape analysis of biomimetic and plasma membrane vesicles

Giant membrane vesicles (GUVs) and Giant plasma membrane vesicles (GPMVs) are models for examining membrane properties. We attempted to conduct a comparative study of reduced volume of vesicles with different lipid compositions, solution symmetry, solution asymmetry, and membrane charge. The vesicular morphology is studied using three-dimensional visualization techniques. The vesicles may not be exactly similar to spheres, but they may have some fluctuations resulting in changes in their shape. To understand these shape deformations, we visualize them as confocal image stacks. Our experimental observations indicate that the charge of the membrane affects the deflation of the GUVs in the presence of trans-bilayer sugar asymmetries. The lipid bilayers of our GUVs contain a uniform distribution of the lipids in the two leaflets, which implies that the two leaflets have the same lipid composition and there is no asymmetries in this composition. However, they obtain trans-bilayer asymmetries through asymmetric adsorption or desorption layers of different solution compositions adjacent to each leaflet. The deformation of the GPMVs shapes extracted from cells with trans-bilayer buffer asymmetries and the composition asymmetries is also estimated and compared with biomimetic membranes.

biophysics↗