Choh Hao Li (sometimes ''Cho Hao Li'') (; April 21, 1913 – November 28, 1987) was a Chinese-born American biochemist who discovered, in 1966, that human pituitary growth

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

(

somatotropin Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in h ...

) consists of a chain of 256

amino acids Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...

. In 1970 he succeeded in synthesizing this hormone, the largest protein

molecule A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioch ...

synthesized up to that time. Li was born in

Guangzhou Guangzhou (, ; ; or ; ), also known as Canton () and alternatively romanized as Kwongchow or Kwangchow, is the capital and largest city of Guangdong province in southern China. Located on the Pearl River about north-northwest of Hong Kon ...

and educated at the

Nanjing University Nanjing University (NJU; ) is a national public research university in Nanjing, Jiangsu. It is a member of C9 League and a Class A Double First Class University designated by the Chinese central government. NJU has two main campuses: the Xianl ...

. In 1935 he immigrated to the US, where he took up postgraduate studies at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California) is a public land-grant research university in Berkeley, California. Established in 1868 as the University of California, it is the state's first land-grant u ...

and later joined the staff. He became professor in 1950. He served as Director of the Hormone Research Laboratory at Berkeley from 1950 to 1967 and at UCSF from 1967 until his retirement in 1983. In 1955 he was elected as Academician of

Academia Sinica Academia Sinica (AS, la, 1=Academia Sinica, 3=Chinese Academy; ), headquartered in Nangang, Taipei, is the national academy of Taiwan. Founded in Nanking, the academy supports research activities in a wide variety of disciplines, ranging from ...

, Republic of China. Li spent his entire academic career studying the pituitary-gland hormones. In collaboration with various co-workers, he isolated several protein hormones, including adrenocorticotropic hormone (ACTH), which stimulates the

adrenal cortex The adrenal cortex is the outer region and also the largest part of an adrenal gland. It is divided into three separate zones: zona glomerulosa, zona fasciculata and zona reticularis. Each zone is responsible for producing specific hormones. It is ...

to increase its secretion of

corticoids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involve ...

. In 1956, Li and his group showed that ACTH consists of 39 amino acids arranged in a specific order, and that the whole chain of the natural hormone is not necessary for its action. He isolated another pituitary hormone called

melanocyte-stimulating hormone The melanocyte-stimulating hormones, known collectively as MSH, also known as melanotropins or intermedins, are a family of peptide hormones and neuropeptides consisting of α-melanocyte-stimulating hormone (α-MSH), β-melanocyte-stimulating h ...

(MSH) and found that not only does this hormone produce some effects similar to those produced by ACTH, but also that part of the amino acid chain of MSH is the same as that of ACTH.

Scientific Achievements

In 1940, Dr. Li successfully purified the luteinizing hormone from sheep

pituitary glands In vertebrate anatomy, the pituitary gland, or hypophysis, is an endocrine gland, about the size of a chickpea and weighing, on average, in humans. It is a protrusion off the bottom of the hypothalamus at the base of the brain. The hypoph ...

. The whole process included grinding thousands of glands, extracting the hormone, and then identifying its chemistry and biology at the molecular level. This was a breakthrough in biological studies. Eight of the nine hormones secreted by the anterior pituitary were isolated and identified by Dr. Li and his research team. These nine hormones can be divided into three groups based on the similarity of their chemical properties and biological activities. The first group includes adrenocorticotropic hormone (ACTH), melanocyte-stimulating hormones (MSH), and

lipotropin Lipotropin is the name for two hormones produced by the cleavage of pro-opiomelanocortin (POMC). The anterior pituitary gland produces the pro-hormone POMC, which is then cleaved again to form adrenocorticotropin (ACTH) and β-lipotropin (β-LP ...

. 1953 - Dr. Li being the first person to isolate and extract ACTH. 1964 - Dr. Li and his research team discovered and isolated lipotropin, and its structure was defined in 1965. 1975 - Dr. Li discovered

β-endorphin ''beta''-Endorphin (β-endorphin) is an endogenous opioid neuropeptide and peptide hormone that is produced in certain neurons within the central nervous system and peripheral nervous system. It is one of three endorphins that are produced in ...

when they were trying to find

β-lipotropin Lipotropin is the name for two hormones produced by the cleavage of pro-opiomelanocortin (POMC). The anterior pituitary gland produces the pro-hormone POMC, which is then cleaved again to form adrenocorticotropin (ACTH) and β-lipotropin (β-LP ...

in camel brain. The team isolated human

in 1976 and synthesized it to study its biological activity after they defined the structure of β-endorphin. The second group includes

follicle stimulating hormone Follicle-stimulating hormone (FSH) is a gonadotropin, a glycoprotein polypeptide hormone. FSH is synthesized and secreted by the gonadotropic cells of the anterior pituitary gland and regulates the development, growth, pubertal maturation, an ...

(FSH), luteinizing hormone (LH), and thyroid stimulating hormone (TSH). 1974 - Dr. Li and his team sequenced human LH and TSH. The third group includes growth hormone and

prolactin Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pit ...

. 1944 - Dr. Li was the first person to isolate growth hormone from cow brains. The lack of function of cow growth hormone on human body motivated Dr. Li to find human growth hormone. 1969 - Dr. Li discovered the complete primary structure of sheep prolactin. 1956 - Dr. Li successfully isolated human and monkey growth hormone and demonstrated its efficacy to treat

hypopituitary Hypopituitarism is the decreased (''hypo'') secretion of one or more of the eight hormones normally produced by the pituitary gland at the base of the brain. If there is decreased secretion of one specific pituitary hormone, the condition is know ...

children. 1970 - Dr. Li synthesized proteins with human

growth hormone Growth hormone (GH) or somatotropin, also known as human growth hormone (hGH or HGH) in its human form, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important in h ...

activity.

Awards

Dr. Li is an expert in diversified areas, including endocrinology, biochemistry, and peptide synthesis. He not only was a widely recognized leader in pituitary-secreted research for his contribution in hormone and growth factors, but also greatly advanced the field of protein chemistry. All of his research had direct impact on clinical applications, especially in growth and fertility. It is estimated that he had published more than 1,000 research papers and had collaborated with more than 300 people. In addition, he was also the recipient of a lot of honors (more than 25). The most significant ones include: 1947
the Ciba Award from the Endocrine Society
1951 - the Award of American Chemical Society 1955
the Amory Prize of American Academy of Arts and Sciences
1962 - the firs
Albert Lasker Award for Basic Medical Research
1970
the Scientific Achievement Award from American Medical Association
1971 - the National Award of the American Cancer Society 1972 -
the Nicholas Andry Award from the Association of Bone and Joint Surgeons
1977 -
the Lewis Price of the American Philosophical Society
1979 - the

William H. Nichols Medal The William H. Nichols Medal is awarded annually for original research in chemistry. Nominees must have made a "significant and original contribution in any field of chemistry" during the five years preceding the presentation date. The medallist ...

of the American Chemical Society 1981
the Koch Award of the Endocrine Society
1987 - the Alan E. Pierce Award (no
R. Bruce Merrifield Award
from American Peptide Society Dr. Li was elected 1958 - Academician of Academia Sinica 1963 - Member of American Academy of Arts and Sciences 1973 - Member of United States National Academy of Sciences 1978 - Foreign Member of Chilean Academy of Sciences 1984 - Foreign Member of Indian Institute of Science

10 Honorary Degrees

1962 - Catholic University of Chile 1970 - Chinese University of Hong Kong 1971 - (the year the synthesis of Human Growth Hormone was announced) * University of the Pacific * Marquette University * Saint Peter's College 1977 - University of Uppsala, Sweden 1978 - University of San Francisco 1979 - Long Island University 1981 - University of Colorado 1982 - Medical College of Pennsylvania

The Establishment of Institute of Biological Chemistry, Academia Sinica

Despite his significant scientific achievements, Dr. Li was also dedicated to the initiation and development of protein research in Taiwan. In spring 1958, Dr. Li was invited by Dr. Shih Hu to lecture a three-week course regarding the newly developed technology in protein chemistry and his latest pituitary gland research at National Taiwan University with the support from China Foundation for the Promotion of Education and Culture. At that time, the academic community only knew that protein research was developing rapidly abroad and a scholar had already made extraordinary achievements, and so when Dr. Li introduced the first-hand knowledge, it really attracted and inspired domestic scientists. Dr. Li believed that the protein chemistry was the foundation of future biochemical and biological sciences research, so he decided to assist the establishment of domestic protein research institute. In order to cultivate talents in Taiwan, Dr. Li personally provided scholarships and selected and persuaded scholars who have settled in Taiwan to continue the research in his or other research institutes. With the support from Academia Sinica, National Science Council, Ministry of Education, and National Taiwan University, Institute of Biological Chemistry and Institute of Biochemical Sciences, College of Life Science, National Taiwan University were established in 1972. The two institutes were originally located in the National Taiwan University's campus (Institutes of Biological Chemistry moved to Academia Sinica's campus later) to integrate research institutes and the University. Dr. Li had always been serving the chief consultant to assist the collaboration of the two institutes and international networking. The achievement of the two institutes today are built on Dr. Li's hard work. Dr. Li's foresight also brought about the domestic development of biotechnology and genetic engineering.

References

* * * * * *

External links

Institute of Biological Chemistry, Academia Sinica
* ttps://oac.cdlib.org/findaid/ark:/13030/tf738nb543/entire_text/ Register of the Choh Hao Li Papers, 1937-1987, Online Archive of Californiabr>Li, Choh Hao, Social Networks and Archival Context

Choh Hao Li Papers
– University of California, San Francisco Library, Archives and Special Collections
Forgotten Superheroes of Science and Medicine: Choh Hao Li

National Academy of Sciences Biographical Memoir
{{DEFAULTSORT:Li, Choh Hao 1913 births 1987 deaths 20th-century biologists American biologists Biologists from Guangdong Chinese emigrants to the United States Educators from Guangdong Members of Academia Sinica Nanjing University alumni People from Panyu District Recipients of the Albert Lasker Award for Basic Medical Research University of California, Berkeley alumni University of California, Berkeley College of Letters and Science faculty University of Nanking alumni