Bottom-up approach to explore alpha-amylase assisted membrane remodelling.

Soluble alpha-amylases play an important role in the catabolism of polysaccharides. In this work, we show that the malt α -amylase can interact with the lipid membrane and further alter its mechanical properties. Vesicle fluctuation spectroscopy is used for quantitative measurement of the membrane bending rigidity of phosphatidylcholines lipid vesicles from the shape fluctuation based on the whole contour of Giant Unilamellar Vesicles (GUVs). The bending rigidity of the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine lipid vesicles in water increases significantly with the presence of 0.14 micromolar alpha-amylase (AA) in the exterior solution. It appears that the enzyme present in the external solution interacts with the outer layer of the bilayer membrane, leading to an asymmetry of the solution on either side of the bilayer membrane and altering its elasticity. At AA concentration of 1.5 micromolars and above, changes in the morphology of the GUV membrane are observed. The interaction between AA in the external solution and the external leaflet causes the bilayer membrane to curve spontaneously, leading to the formation of outbuds, giving a positive spontaneous curvature of C0 ≤ 0.05 µm-1 at ≈ 1 mg / ml of the AA concentration. We validate and characterize its concentration-dependent role in stabilizing the membrane curvature. Our findings indicate that the involvement of the enzyme, depending on the concentration, can have a considerable effect on the mechanical characteristics of the membrane.

Impact of UDST: A step forward to end TB.

BACKGROUND: India is determined to eliminate TB by 2025 despite being a high burden country. Revised National Tuberculosis Control Programme (RNTCP) is being strengthened with introduction of Universal Drug Susceptibility Testing (UDST) for Rifampicin to achieve the elimination status. METHODOLOGY: We used a before-after comparison of baseline and intervention periods (12 months each) and analyzed data viz CBNAAT performed and case detection for both drug sensitive and drug resistant TB cases. RESULTS: After implementation of Universal DST, CBNAAT performed raised from 1252 to 3137 (increased by 2.5 times); Rif sensitive cases detected raised from 458 to 1241 (increased by 2.7 times) and Rif resistant cases detected raised from 54 to 82 (increased by 1.5 times) during baseline period (2017) and intervention period (2018). CONCLUSION: We conclude that introduction of UDST for Rifampicin in RNTCP has given a significant impact with increased case detection in our study.