ASBMB Nobel Prize Winners

1946 – James B. Sumner



James Batcheller Sumner (1887 –1955) was awarded the 1946 Nobel Prize in Chemistry for showing that enzymes can be crystallized.  Sumner’s initial attempt to isolate an enzyme in pure form -- a feat which had never been achieved before -- centered on urease, which catalyzes the hydrolysis of urea into carbon dioxide and ammonia.  He successfully isolated and crystallized urease in 1926. Later, he crystallized catalase -- the enzyme catalyzing the decomposition of hydrogen peroxide to water and oxygen --  and worked on purifying various other enzymes, which led him to discover that most enzymes are proteins.