Urease, the First Crystalline Enzyme and the Proof That Enzymes Are Proteins: the Work of James B. Sumner
Year: 2002
Type: article
Abstract: The Isolation and Crystallization of the Enzyme Urease. Preliminary Paper (Sumner, J. B. (1926) J. Biol. Chem. 69, 435–441 ) The Digestion and Inactivation of Crystalline Urease by Pepsin and by Papain (Sumner, J. B., Kirk, J. S., and Howell, S. F. (1932) J. Biol. Chem. 98, 543–552 ) James Batcheller Sumner (1887–1955) was born in Canton, MA, near Boston. As a boy, he had many interests including hunting. During an afternoon of hunting with a friend, the friend accidentally shot Sumner in the arm requiring that it be amputated above the elbow. He worked his entire life to be sure that this handicap did not interfere with his goals and aspirations. He enrolled in Harvard College in 1906 planning to study electrical engineering but lacked the necessary mathematics training so he changed his field to chemistry and graduated in 1910. After a year teaching chemistry at Worcester Polytechnic Institute, he returned to Harvard to study for his Ph.D. It had been suggested that he work with Otto Folin, Chairman of the Biochemistry Department at Harvard Medical School, and author of a previousJournal of Biological Chemistry (JBC) Classic (1Folin O. Wu H. J. Biol. Chem. 1919; 38 (JBC Classics): 81-110http://www.jbc.org/cgi/content/full/277/20/e9Abstract Full Text PDF Google Scholar). Folin told him during the interview that he should consider law school because “a one armed man could never make it in chemistry.” Sumner, challenged by this remark, did his thesis work with Folin. He graduated in 1914 with his thesis on “The Formation of Urea in the Animal Body” and with Folin's admiration. During the summer of 1914, Sumner accepted an offer as Assistant Professor in the Department of Physiology and Biochemistry in the Ithaca Division of Cornell University Medical College. He would serve his entire career at Cornell in Ithaca in various departments and schools as the University reorganized itself. Sumner was the pioneer in biochemistry in Ithaca and remained a leader for over 40 years. In spite of a very heavy teaching responsibility and little technical support, Sumner chose isolation of an enzyme in pure form for his research program. During his Nobel Laureate lecture in 1948, he offered an explanation: “I wish to tell next why I decided in 1917 to attempt to isolate an enzyme. At that time I had little time for research, not much apparatus, research money or assistance. I desired to accomplish something of real importance. In other words, I decided to take a long shot. A number of persons advised me that my attempt to isolate an enzyme was foolish, but this advice made me feel all the more certain that if successful the quest would be worthwhile.” It would take nine years before his goal was reached and many more years before his work was generally accepted. (How many Assistant Professors would survive today with this record?). In the first paper of this set of JBC Classics, Sumner reports crystallization of a new globulin isolated from jack bean meal and presents evidence that the globulin was identical with the enzyme urease. The crystallization is from a water/acetone extract of jack bean meal allowed to stand in the cold overnight. Sumner presents extensive experimental evidence that the crystalline material is the enzyme urease including the observation that the most active preparations of urease they had prepared had a specific activity of 30,000 units/g of enzyme whereas the dissolved crystals had a specific activity of 100,000. The publication of this Classic paper and the evidence that an enzyme, urease, was a protein was met with skepticism by most and disbelief by others. Most critical were Willstater and his students in Germany who had tried for many years to isolate a pure enzyme and, having failed, concluded that pure enzymes contained no protein. They dismissed Sumner's work concluding that the protein that had been crystallized was the carrier for the enzyme that had been adsorbed to it. Sumner followed the initial report with ten papers reporting additional evidence that the globulin he had crystallized was the enzyme urease. One of these supporting papers is the second in this set of JBC Classics. Using proteolytic enzymes, papain and pepsin, Sumner and his colleagues show that proteolysis of urease results in loss of enzymatic activity. The case that enzymes were proteins was given a boost in 1930 when J. H. Northrup at Rockefeller Institute reported the crystallization of pepsin and later trypsin and chymotrypsin. Only in 1946, with the award of the Nobel Prize, was Sumner's work fully accepted. He received the award “for his discovery that enzymes can be crystallized.” The other half of the award went to J. H. Northrup and Wendell Stanley “for their preparation of enzymes and virus proteins in pure form.” Sumner retired in July 1955 and died of cancer a month later. 1All the biographical information for the Classic Introduction was taken from Ref. 2Maynard L.A. Biographical Memoir of James Batcheller Sumner. 31. National Academy of Sciences, Washington, D.C.1958: 376-386Google Scholar. 1All the biographical information for the Classic Introduction was taken from Ref. 2Maynard L.A. Biographical Memoir of James Batcheller Sumner. 31. National Academy of Sciences, Washington, D.C.1958: 376-386Google Scholar.
Source: Journal of Biological Chemistry
Language: English
Subfield: History and Philosophy of Science
Field: Arts and Humanities
Domain: Social Sciences
Open Access status: hybrid
Estimated APC paid: $3,430
OpenAlex ID: W1557507368