
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.