Investigating the triolein/aqueous interface and Thermomyces lanuginosa lipase activity

Sammanfattning: The triglyceride/ aqueous interface has an important role in many processes, e.g. lipase activity. Lipase is responsible for the degradation of triglycerides to smaller components, such as fatty acids. The enzyme attracts interest in industrial applications of the catalytic behavior it possesses, such as in food and pharmaceutical industries. Thus, understanding the interface which is controlling its activity, is of importance. The emulsification and the interface of triolein and water is investigated in terms of water inclusion and Thermomyces lanuginosa lipase (TLL) activity, to gain information about the workings of the interface and TLL relation. Based on measurements of the thickness change of a triolein film over time, using spectroscopic ellipsometry (SE), the water uptake in the triolein phase appears to increase when active or inactive TLL is present in the aqueous solution. The presence of TLL was further investigated with small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS), which suggested a longer repeat distance of triolein molecules when active TLL is present than if it is not. This suggests bigger aggregates are formed with more water uptake, when the triolein molecules are degraded. The obtained scattering data is preliminary. The information gained from SE unfolds a portion of the molecular interactions between TLL and the lipid/aqueous interface, by indicating different trends of thickness variations of triolein, when active TLL or inactive TLL is present.