Johann Deisenhofer (German pronunciation: [ˈjoːhan ˈdaɪzn̩ˌhoːfɐ] ⓘ; born September 30, 1943) is a German biochemist who, along with Hartmut Michel and Robert Huber, received the Nobel Prize for Chemistry in 1988 for their determination of the first crystal structure of an integral membrane protein, a membrane-bound complex of proteins and co-factors that is essential to photosynthesis.

[2][3][4][5] Born in Bavaria, Deisenhofer earned his doctorate from the Technical University of Munich for research work done at the Max Planck Institute of Biochemistry in Martinsried, West Germany, in 1974.

This membrane protein complex, called a photosynthetic reaction center, was known to play a crucial role in initiating a simple type of photosynthesis.

Their research increased the general understanding of the mechanisms of photosynthesis and revealed similarities between the photosynthetic processes of plants and bacteria.

[6] Deisenhofer currently serves on the board of advisors of Scientists and Engineers for America, an organization focused on promoting sound science in American government.