Speaker
Description
Fatty acid Langmuir monolayers and multilayers are very fascinating two-dimensional system formed at the air-water interface. These layers show thermodynamically metastable behaviours through different phases and phase transitions. Langmuir-Blodgett (LB) films provide the transfer of monolayer onto solid surfaces to study their morphological, structural, and optical properties. Similarly, protein adsorption on fatty acid monolayers/ bilayers may show cell membrane-protein interactions at the molecular level. The structural, optical behaviours of proteins change as they get attached or adsorb onto any solid surface which leads to changes in the proteins' physiological functional behaviour. In this study, we try to understand how fatty acid monolayers and multilayers affect the adsorption of globular protein Bovine Serum Albumin (BSA) and structural modifications of BSA proteins as well. In this study Arachidic acid monolayer and tri-layer LB films had been prepared in presence of Barium ion in the Subphase on Si (100) hydrophilic substrate at Subphase pH ≈ 7.0. X-Ray Reflectometry (XRR) and Atomic Force Microscopy (AFM) data confirms the deposition of Ba-Arachidate (BaAr) monolayer and tri-layer on Si (100) substrate. After that adsorption of BSA protein molecules on the LB film surfaces had been done on different solution pH at 4.0, 5.0 & 7.0. BSA solution was prepared with Milli-Q water and pH was maintained. The LB films were dipped vertically for about 15 mins and removed from the solution and let the sample dry in vertical position. XRR and AFM data clearly reveals the morphological and structural information of BSA adsorption as well as the structural change of the underlying fatty acid layers in presence of different solution pH. To confirms the BSA proteins conformational changes FTIR data were taken in the Attenuated Total Reflectance (ATR) mode of all films. ATR-FTIR data reveals the BSA conformational changes which was expected. Change of BSA surface charge with proteins and the modifications in the hydrophobic-hydrophobic interactions plays key role in the adsorption of proteins on the BaAr monolayer and tri-layer LB films. Further analysis of the data will provide more insights of the interactions and among the BSA protein molecules and the BaAr fatty acid layers.
