Protein Prober

The intense young man who went to Harvard as an assistant professor in 1922 was no physician but a biochemist, ready to dedicate his life to probing the secrets of proteins. He would never get to treat a patient. But across the U.S. and around the world, hundreds of thousands are alive and well today, thanks to his biochemistry, and the vast majority of his beneficiaries have never so much as heard his name.

Edwin Joseph Cohn, son of a wealthy Manhattan tobacco importer, had just finished his doctoral thesis when World War I drew him into the Army Sanitary Corps. There he was sidetracked on an unrewarding assignment: trying to find a substitute for bread. As soon as possible, Scientist Cohn returned to his beloved proteins, learned what others knew about them in Copenhagen and Cambridge, then settled at Harvard to find out what nobody else knew.

No Time to Retire. By the time he was 40, Edwin Cohn had an imposing reputation in the narrow circle of protein specialists, and nowhere else. Then his doctors told him to retire: his high blood pressure might kill him any day. Dr. Cohn simply dosed himself with palliative drugs and kept on working. His first great success so far as medicine was concerned came in 1927 when he extracted from liver the substance that controls pernicious anemia. It meant that patients could take medicine, instead of having to eat a pound or more of liver every day.

When the clouds gathered for World War II, Cohn was again sidetracked, as he saw it, from his protein work. The armed forces wanted to be assured of a supply of blood plasma, and the Navy thought Cohn should try to get it from beef blood because human donors would never suffice. Cohn found beef blood unpromising, and started a neighborhood donor service from which the Red Cross learned a lot. So the armed forces used human plasma.

But to Cohn, a perfectionist, this was grossly wasteful. Usually, only one or two components of plasma were needed for each case. So he set to work in his laboratory, separating blood fluid into its many fractions, and soon had a practical method for extracting serum albumin. This was less bulky than plasma, kept better, and was far more economical. But it was not good enough for Cohn.

No Shotgun Blast. Driving himself as relentlessly as he drove the assistants who performed the practical experiments to prove his brilliant theoretical flashes, Cohn identified more and more of the components of blood, and developed improved methods for extracting many of them. There was fibrinogen, raw material from which fibrin film and fibrin foam are made, to close wounds and cover the brain in daring, delicate surgery. There was thrombin, which combines with fibrinogen but is used separately in some cases. There was a special kind of globulin for hemophiliacs. There were globulins which made possible the immediate typing of any individual's blood.

Finally--and so far the most important--was gamma globulin, which prevents measles or softens its severity, and wards off infectious hepatitis. Most recently, gamma globulin has won fame in the fight against polio. A less exacting researcher might have been satisfied, but not Cohn. He hated the waste (and doubted the wisdom) of using whole gamma globulin as a shotgun blast against any of three diseases, and wanted to break it down into still finer fractions for pinpoint use against each disease.

Last week portable fractionators of thinking-machine complexity were being built to Cohn's specifications for taking blood direct from a donor's arm and fractionating it on the spot (TIME, Oct. 23, 1950). Cohn had just summed up his life's work and theories in a paper forbiddingly entitled "Evidence and Consequence of the Fine Structure of Protein." As he was about to circulate copies to the handful of other protein men who could understand it, Biochemist Cohn's blood pressure caught up with him. He had a cerebral hemorrhage and died, aged 60. It will take years of complex laboratory work to prove or disprove the theories on the synthesis of proteins which Cohn propounded in his last paper. "But," said a grieving assistant gratefully, "at least we have that."

This file is automatically generated by a robot program, so reader's discretion is required.