27-MAY-1987 :- Death Of John Howard Northrop , American Biochemist, Nobel Prize winner.

John Howard Northrop 
(July 5, 1891 – May 27, 1987) was an American biochemist who won, with James Batcheller Sumner and Wendell Meredith Stanley, the 1946 Nobel Prize in Chemistry. The award was given for these scientists' isolation, crystallization, and study of enzymes, proteins, and viruses. Northrop was a Professor of Bacteriology and Medical Physics, Emeritus at University of California, Berkeley.

In 1929, Northrop isolated and crystallized the gastric enzyme pepsin and determined that it was a protein. In 1938 he isolated and crystallized the first bacteriophage (a small virus that attacks bacteria), and determined that it was a nucleoprotein. Northrop also isolated and crystallized pepsinogen (the precursor to pepsin), trypsin, chymotrypsin, and carboxypeptidase.

For his 1939 book, Crystalline Enzymes: The Chemistry of Pepsin, Trypsin, and Bacteriophage, Northrop was awarded the Daniel Giraud Elliot Medal from the National Academy of Sciences. He was elected a Fellow of the American Academy of Arts and Sciences in 1949. Northrop was employed by the Rockefeller Institute for Medical Research in New York City from 1916 until his retirement in 1961. In 1949 he was appointed Professor of Bacteriology, University of California, Berkeley and later, Professor of Biophysics.