Expression, purification and characterization of Gap1expressed using the nitrogen catabolite repression promoter system. A) Schematic representation of the medium switch protocol. B) Expression control of Gap1 by western blot revealed by an antibody against penta-histidines. Samples were taken just before the switch to the inductive medium (1), one hour after medium switch (2), 2 hours (3) and 23 hours just before harvesting the cells (4). C) Purity control by SDS-PAGE of Gap1 after purification using affinity chromatography. The protein is revealed by Coomassie staining. D) Infrared spectrum of reconstituted Gap1 in yeast lipid extract, peak of C = O bounds of lipids and proteins are highlighted.