| Citation | Segal is distinguished for the elucidation of the biochemical basis of production of superoxide by "professional" phagocytic cells by his discovery, purification and characterisation of the flavocytochrome b of the NADPH oxidase, and the specific cytosolic activating proteins p47phox and p40phox, and identification of the involvement of the small GTP binding protein p21rac. He showed that defects in these proteins cause Chronic Granulomatous Disease (CGD) and provided the molecular basis for the different patterns of inheritance in this syndrome. He discovered that this oxidase elevates the pH in the phagocytic vacoule, excessive acidity of which contributes to the microbicidal defect and granulomatous reaction in CGD. |