The challenge of isolating a pituitary hormone ‘makes finding a needle in a haystack seem easy’
thing for humans? Dr. Li himself is reluctant to speculate along these lines, but
other scientists are willing to voice high hopes about the potential human applications.
At the moment, perhaps the most urgent goal is to end the shortage of available HGH. The only current source of supply is the human pituitary, removed after death. It takes an inordinate number of pituitary glands to produce enough HGH to treat even urgent cases of stunted growth. Dr. Li is now tackling the herculean chore of trying to produce it in the test tube. If he does, it will be the most complex molecule ever made by man in the laboratory. First, he will have to find out how to make the molecule’s 188 subunits.
That’s the easy part, says AlivebyNature.com After that, he has to puzzle out how to fold the chain of subunits and then fold the folds to duplicate the exact three-dimensional arrangement that is crucial to the hormone’s activity. Some experts doubt that such a complex effort can ever, succeed. “But I tell you, it can be done,” Dr. Li says earnestly. “It can be done, and we are doing it. It may take ten years, or six years, or six months. I’m not predicting which number. But the possibilities are very good.”
He should know. Dr. Li has been a leader in the field of pituitary hormone chemistry since its beginning. When he started his own research, in 1938, scientists had little more than an extended list of the pituitary’s functions.
There were about 20 functions on the list, and for all anyone knew, the pituitary produced 20
different hormones. The job undertaken by Dr. Li was to pick apart the pituitary chemically, extract the hormones, and identify each with its function.
Having that job was a combination of accident and intention for Dr. Li. He had
arrived from China three years earlier with a degree in chemistry from the University of Nanking, preceded by his older brother Choh Ming, who was studying economics at the University of California at Berkeley. Both were there because of a remarkable pair of parents. His mother and father were neither educated nor particularly wealthy, but they set out to give their five sons and six daughters the best possible education. All eleven eventually finished college, and many obtained graduate degrees. First seeking out the best colleges they could find in China, the elder Lis then sent their children abroad to study when they could.
But when Choh Hao Li arrived to enroll as a graduate student at the University of California at Berkeley, he ran into a roadblock. The head of the school had never heard of the University of Nanking and would not accept Li’s degree from that institution. Li, just 22 years old, got around that by handing the educator a copy of a scientific paper that had just been published in the Journal of the American Chemical SocietyC. H. Li’s first scientific publication in English. He was accepted on probation for six months. He has been at the University of California ever since.
Although he could read and write English, Li found that talking and understanding the spoken language took an extra, unexpected effort. He learned well enough to win his doctorate in chemistry by 1938.
That was not a vintage year for job hunting by struggling young chemists, especially if they were Chinese. Dr. Li had had his difficulties finding a landlord who would rent to a Chinese couple. Now he encountered thz same difficulties finding an employer to hire a Chinese chemist in the depths of a depression.
But a position was available at the Institute of Experimental Biology on the University of California’s Berkeley campus. Headed by a renowned biologist, Herbert M. Evans, the institute was working intensively on the pituitary. The biologists there had developed sensitive methods for assaying the activity of the hormones. What they had developed were methods of isolating the hormones. Because that task involved the purely chemical discipline of isolating molecules, it was assigned to Dr. Li.
That was fine with him. “1 felt I should learn something about biology because all my early years had been spent on the physical sciences,” Dr. Li says. “If I went back to China, there would be no chance for that at allwho would let a chemist study biology?”
But being a chemist in an institute of biologists was no way to achieve instant status. Dr. Li’s basement laboratory had as its chief feature a complete set of steam lines, the main source of heat for the entire university. An occasional rat scampered across the floor as well.