James Batcheller Sumner | Biography

James Sumner, son of a wealthy cotton manufacturer, learned early in life how to rise to a challenge. When he was 17, Sumner, accidentally shot by a hunting companion, had to have his left arm amputated. Although he had originally been left-handed, the young man retrained himself so well that he continued to excel in sports, becoming a champion tennis player, and a capable skier and mountain climber. Nevertheless, friends and teachers warned Sumner against trying to follow another of his dreams--becoming a chemist.

Ignoring the warnings, Sumner persisted. He studied chemistry at Harvard University, graduated in 1910 and taught for a while. Then, despite another warning from a college official, he returned to Harvard as a graduate student in biochemistry. After receiving his Ph.D. in 1914 he joined the faculty of Cornell Medical College, where he remained until his retirement in 1955.

Throughout his career, Sumner's chief interest was in enzymes, the catalytic agents that play so vital a role in virtually all physiologic processes. Although enzymes had been discovered in yeast cells by Eduard Buchner in 1897, their nature was still a mystery. For years, researchers had assumed they were proteins, but the German chemist Richard Willstätter, a Nobel laureate and the leading expert on enzyme chemistry, asserted that they were not proteins--that they did not, in fact, appear to belong to any known category of organic substances. Moreover, since they were easily destroyed by all known chemical reagents, researchers doubted they would ever be isolated in pure form. Enzymes, in short, were a challenge. Sumner, who relished challenges, decided in 1917 he would try to be the first chemist to isolate one.

The enzyme he chose to work with was urease, the urea-splitting enzyme which was present in relatively high concentrations in the jack bean. His plan of action was simple enough: to characterize as many chemical components in the bean as he could and then, if possible, to separate urease from all the other components. But, as he had expected, the plan presented formidable challenges. Nine long years later, Sumner finally found a solvent, dilute acetone, that destroyed neither proteins nor enzymes. In 1926, he wound up with tiny microscopic crystals that had high urease activity--and that proved to be proteins. Sumner's findings were promptly challenged, though, not only by the highly respected Willstätter but by most of the major European chemists who doubted that an unknown American could come up with the solution that had eluded them for well over 20 years.

For the next decade, the debate raged on both sides of the Atlantic Ocean. Between 1930 and 1935, however, another American biochemist, John Northrop, managed to isolate several more enzymes, including pepsin and trypsin, and agreed with Sumner that they were indeed proteins. A few Europeans, too, such as Otto Warburg, also gradually sided with Sumner. By 1937, Sumner's work was fully accepted, and in 1946 he received the Nobel Prize in chemistry, sharing it with Northrop and Wendell Stanley.