This proposal seeks to shed light on the functional and structural characteristics of a specific membrane protein - cytochrome P450 reductase (abb. POR) - part of the cytochrome P450 superfamily from the subtropical crop plant Sorghum Bicolor. POR is believed to function through association with other enzymes, thus forming large enzymatic complexes (metabolons). Our method of investigation involves capturing POR in nanodiscs, nano-sized circular patches of lipid bilayer held together by membrane scaffold proteins. POR acts as an electron donor in a NADPH-dependent manner, which is accompanied by large conformational changes detectable through neutron reflection. The strategy is to immobilize POR-loaded nanodiscs on SiO2-surfaces at INTER, flush with appropiate cofactors to clarify the origin of the shift in conformational equilibrium as a function of lipid phase (through temperature).