Mary Bernheim

Mary Lilias Christian Bernheim (née Hare; 1902–1997) was a British biochemist best known for her discovery of the enzyme tyramine oxidase, which was later renamed as monoamine oxidase. Bernheim discovered the enzyme system of tyramine oxidase during her doctorate research at the University of Cambridge. Bernheim's discovery of tyramine oxidase has been referred to as "one of the seminal discoveries in twentieth century neurobiology".

Early life and education

Bernheim was born under the name Mary Lilias Christian Hare in Gloucester, England in 1902. However, she was referred to as “Molly” by those around her. As a child, Bernheim was raised in India. She eventually obtained higher degrees of BA, MA, and PhD from the University of Cambridge in England. After finishing her undergraduate at the University of Cambridge, Bernheim received the Bathurst Studentship to work in the Department of Biochemistry at the Newnham College.

Discovery of monoamine oxidase

As a doctoral student at the University of Cambridge, Bernheim discovered the enzyme tyramine oxidase as part of her dissertation research in 1928. Prior to her discovery, tyramine had not been studied extensively from a biochemical perspective.

As part of her research, Bernheim utilized liver extracts from rabbits and extracted the enzyme by adding kaolin at the proper pH. After the crude tyramine had been extracted, the Barcroft technique was used to observe levels of oxygen consumption. She discovered that the oxidation of tyramine took place, with the observation that one atom of oxygen was absorbed per molecule of tyramine present. This observation indicated the presence of an enzyme system, namely tyramine oxidase, within the studied liver extracts.

Within the enzyme system, Bernheim observed that the methylene blue present was not reduced. Furthermore, she detected the occurrence of deamination within the enzyme, along with the process of oxidation. Unlike other similar pathways, the oxidative process within this enzyme system was seen to be resistant to cyanide.

Importance of monoamine oxidase discovery

Following her discovery, Bernheim predicted that tyramine oxidase was important for detoxing the extra amines absorbed from the intestines. However, later research indicated that catecholamines and histamine were substrates in the process, resulting in the enzyme being renamed as monoamine oxidase.

After the discovery of monoamine oxidase, there were numerous studies conducted on the biological importance of monoamines. Upon discovering that the anti-depressant iproniazid was a monoamine inhibitor, there was a marked increase in pharmacological research on drugs regulating monoamine activity.

Duke Medical School faculty

In 1930, Bernheim was appointed onto the original Duke Medical School faculty alongside her husband Dr. Frederick Bernheim. At the time of her death in 1997, she was the final surviving member of the original faculty. During her time at Duke, Bernheim was notably one of few women in the Department of Biochemistry, either as a student or faculty member. In 1962, she became a full professor and was teaching nursing students.

Personal life

While at Cambridge, Hare met fellow graduate student Frederick Bernheim, and eventually married him on December 17, 1928. Dr. Fredrick Bernheim was nominated for the Nobel Prize in 1940 for his pharmacological research on the tuberculosis bacteria. Bernheim has authored over sixty papers, including a paper on the function of pyrrole as a catalyst, which she published with her husband.

Beyond biochemistry, Bernheim had interests in botany and flying. She published a book "A Sky of My Own," in which she details her journey into the field of flying, and describes her experience as a pilot and flight instructor.

Bernheim was recognized for her contributions to scientific research, and she was honored at the Ciba Foundation symposium held in 1975 for her discovery of monoamine oxidase. Although she retired in 1983, she remained in a teaching position until her death in 1997 at the age of 95.