Paper Title
Interaction of UREASE/DOPC Hybrid System at Air-Water and Air-Solid Interface

Abstract
Understanding the interactions of proteins at the interface of lipid structures is important for biological systems and subsequently the topic has become of widespread interests in a variety of fields such as in biomedical and biochemical research, biosensing and food science.[1],[2]In the present study, the protein-lipid interactions between water-soluble metalloenzyme urease and the water-insoluble phospholipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)were investigated at the air-water interface using the Langmuir-Blodgett (LB) technique. Surface pressure-molecular area (Π – A) isotherms were measured for the DOPC monolayer in presence of urease in the water subphase (Figure 1a) and a strong conjugation was found between urease and DOPC. The compressibility of the DOPC monolayer was reduced with the incorporation of urease (Figure 1b).The Atomic Force Microscopy (AFM) shows strong conjugation between urease and DOPC in hydrophilic surface (see Figure 1c). However, in hydrophobic surface the urease molecules denatured rigorously probably due to exposure of the tryptophan moiety towards hydrophobic air environment.