Albumin-fatty acid interactions at monolayer interface

作者：Gew Lai Ti^*; Misran Misni

来源：Nanoscale Research Letters, 2014, 9(1): 218.

DOI：10.1186/1556-276X-9-218

• Lipid-protein interaction
• Protein
• Stearic acid
• Bovine serum albumin
• Langmuir
• Atomic force microscopy

The fluid mosaic model of Singer and Nicolson in 1972 shows how proteins are embedded in membranes. To elucidate the interactions between proteins and the surrounding lipids, stearic acid (SA) and bovine serum albumin (BSA) were used as lipid-protein components to mimic the normal membrane bilayer environment using the Langmuir-Blodgett technique. Surface pressure (pi)-molecular area (A) isotherms were recorded for the SA monolayer in the presence of BSA on water. The mixed monolayer was successfully transferred onto an oxidized silicon wafer and imaged by tapping mode atomic force microscopy (AFM). Miscibility, compressibility and thermodynamic stability of the mixed system were examined. A large negative deviation of A (ex), together with the minimum value of Delta G (ex), was observed when the mole fraction of BSA (X (BSA)) was 0.8, indicating this to be the most stable mixture. In a compressibility analysis, X (BSA) was observed at below 50 mN m(-1), denoting a liquid-expanded phase and showing the occurrence of a strong interaction of SA with BSA molecules in this phase. AFM observations supported the quantitative data indicating that BSA was strongly attracted onto the membrane surface as predicted.

• 出版日期2014-5-7