Hsien Wu (simplified Chinese: 吴宪; traditional Chinese: 吳憲; pinyin: Wú Xiàn; 24 November 1893 – 8 August 1959) was a Chinese protein scientist. He was the first to propose that protein denaturation was a purely conformational change, i.e., corresponded to protein unfolding and not to some chemical alteration of the protein. This crucial idea was popularized later by Linus Pauling and Alfred Mirsky.
Wu was born in Fuzhou, Fujian, China. He studied at MIT (undergraduate), and then trained at Harvard University (graduate) under Otto Folin, developing the first assay for blood sugar (Folin-Wu method). Wu then returned to China to a position at Peking Union Medical College, becoming head of the biochemistry department in 1924 at age 30.
Wu left China in 1947 to reside in the United States.
Wu's son, Ray J. Wu, became the Liberty Hyde Bailey Professor of Molecular Genetics and Biology at Cornell University, and was active in studying transgenic plants, particularly rice.