Maud Menten

The Menten family moved to Harrison Mills, where Maud's mother worked as a postmistress. After completing secondary school, Menten attended the University of Toronto where she earned a bachelor of arts degree in 1904 and a master's degree in physiology in 1907. While earning her graduate degree, she worked as a demonstrator in the university's physiology lab.

As Menten wanted to further her medical research, she found that opportunities in Canada were scarce for women at the time. As a result she accepted a fellowship at the Rockefeller Institute for Medical Research and left for in New York City in 1907; there she studied the effect of radium bromide on cancerous tumors in rats.[6] Menten and two other scientists published the results of their experiment, producing the Rockefeller Institute's first monograph.[6][7] Menten worked as an intern at the New York Infirmary for Women and Children. After a year at the Institute, Menten returned to Canada and began her studies at the University of Toronto where in 1911 she became one of the first Canadian women to qualify as a medical doctor.[6]

In 1912, Menten came back to medical research, working with renowned surgeon George Crile on the control of acid-base balance during anaesthesia. Around this time she became acquainted with Leonor Michaelis, he was known then as one of the world-leading experts in pH and buffers.[8] Menten became attracted to Michaelis' early work in enzyme kinetics, despite his modest laboratory establishment in Berlin, and made the difficult decision to cross the sea to work with Michaelis. Menten's early years in Germany was met with financial and social hardships, she took a paid position at a Berlin hospital to cover her living and travel expense as well as beginning to learn German when she first came to Berlin.[8]

From 1905 to 1921, Michaelis and Menten expressed the relationship they were investigating as an equation:

${\displaystyle v={\frac {Va}{K_{\mathrm {m} }+a}}}$

for a steady-state rate ${\displaystyle v}$ in terms of the substrate concentration ${\displaystyle a}$ and constants V and ${\displaystyle K_{\mathrm {m} }}$ (written with modern symbols). Victor Henri had included an equivalent equation in his thesis, but he did not use it and did not appreciate the importance of the steady state.[9][10] The equation shows not only that each enzyme is specific for its substrate, but also that the rate of reaction rate increases to saturation as the substrate concentration increases. The constant ${\displaystyle K_{\mathrm {m} }}$ used in expressing this rate is now called the Michaelis constant.[11] The paper deriving the Michaelis–Menten equation is Menten's most famous work,.[3]

After her research in Berlin, Menten enrolled in University of Chicago, where in 1916 she obtained a PhD in biochemistry. In 1923, Menten still could not find an academic position for women in Canada; she took a position as part of the faculty of the medical school at the University of Pittsburgh while serving as a clinical pathologist at Children’s Hospital in Pittsburgh. Despite the demands both jobs had, Menten found time to maintained an active research program, authoring or coauthoring more than 70 publications. Although her promotion from assistant to associate professor was timely, she was not made a full professor until she was 70 years old, within one year of retirement.[11]

Menten also invented the azo-dye coupling reaction for alkaline phosphatase, which is still used in histochemistry. This was described in a major textbook of the 1950s[12] in the following terms:

It is not too much to say that the use of this principle was a stroke of genius.

She characterised bacterial toxins from B. paratyphosus, Streptococcus scarlatina and Salmonella ssp. that were used in a successful immunisation program against scarlet fever in Pittsburgh in the 1930s - 1940s.[13] She also conducted the first electrophoretic separation of blood haemoglobin proteins in 1944. She worked on the properties of hemoglobin, regulation of blood sugar level, and kidney function.[14]

After her retirement from the University of Pittsburgh in 1950, she returned to Canada where she continued to do cancer research at the British Columbia Medical Research Institute (1951–1953).

Poor health forced Menten's retirement in 1955, and she died July 17, 1960, at the age of 81, in Leamington, Ontario.[6][2]

Rebecca Skloot portrays Menten as a petite dynamo of a woman who wore "Paris hats, blue dresses with stained-glass hues, and Buster Brown shoes."[6] She drove a Model T Ford through the University of Pittsburgh area for some 32 years and enjoyed many adventurous and artistic hobbies. She played the clarinet, painted paintings worthy of art exhibitions,[2] climbed mountains, went on an Arctic expedition, and enjoyed astronomy. By the time of her death, she mastered several languages, including Russian, French, German, Italian, and at least one Native-American language, Halkomelem.[6][15] Although Menten did most of her research in the United States, she retained her Canadian citizenship throughout her life.

Throughout her career Menten was affiliated with many scientific societies.

At Menten's death, colleagues Aaron H. Stock and Anna-Mary Carpenter honored the Canadian biochemist in an obituary in Nature: "Menten was untiring in her efforts on behalf of sick children. She was an inspiring teacher who stimulated medical students, resident physicians and research associates to their best efforts. She will long be remembered by her associates for her keen mind, for a certain dignity of manner, for unobtrusive modesty, for her wit, and above all for her enthusiasm for research." [14]

In 1998 she was posthumously inducted into the Canadian Medical Hall of Fame.[2] She was also honored at the University of Toronto with a plaque and at the University of Pittsburgh with memorial lectures and a named chair.[6] Port Lambton, Canada, where Menten was born, installed a commemorative bronze plaque about her in 2015.[16]

• Menten, ML.; Willms, M.; Wright, WD. (1953). "Nucleic acid content of splenic lymphocytes in normal and leukemic mice". Cancer Research. 13: 729–732.
• Neale, AE.; Menten, ML. (1948). "Tumors of the thymus in children". American Journal of Diseases of Children. 76: 102–108. doi:10.1001/archpedi.1948.02030030109012.
• Menten, ML.; Fetterman, GH. (1948). "Coronary sclerosis in infancy - report of 3 autopsied cases, 2 in siblings". American Journal of Clinical Pathology. 18 (10): 805–810. doi:10.1093/ajcp/18.10.805.
• Menten, ML.; Janouch, M. (1946). "Changes in alkaline phosphatase of kidney following renal damage with alloxan". Proceedings of the Society for Experimental Biology and Medicine. 63: 33–37. doi:10.3181/00379727-63-15482.
• Troll, MM.; Menten, ML. (1945). "Salicylate poisoning - report of 4 cases". American Journal of Diseases of Children. 69: 37–43. doi:10.1001/archpedi.1945.02020130044006.
• Menten, ML.; Junge, J.; Green, MH. (1944). "Distribution of alkaline phosphatase in kidney following the use of histochemical azo dye test". Proceedings of the Society for Experimental Biology and Medicine. 57: 82–86. doi:10.3181/00379727-57-14706.
• Menten, ML.; Junge, J.; Green, MH. (1944). "A coupling histochemical azo dye test for alkaline phosphatase in the kidney". Journal of Biological Chemistry. 153: 471–477.
• Andersch, MA; Wilson, DA; Menten, ML. (1944). "Sedimentation constants and electrophoretic mobilities of adult and fetal carbonylhemoglobin". Journal of Biological Chemistry. 153: 301–305.
• King, CG.; Menten, ML. (1935). "The influence of vitamin C level upon resistance to diphtheria toxin I. Changes in body weight and duration of life". Journal of Nutrition. 10: 129–140.
• Menten, ML (1927). "Changes in the blood sugar of the cod, sculpin, and pollock during asphyxia". Journal of Biological Chemistry. 72: 249–253.
• Menten, ML (1922). "Pathological lesions produced in the kidney by small doses of mercuric chloride". Journal of Medical Research. 43: 315–321.
• Menten, ML., "A study of the oxidase reaction with a-naphthol and paraphenylenediamine." Journal of Medical Research, Vol 40 (1919) pp. 433 - U22
• Michaelis L., Menten, ML. "The kinetics of invertin action" Biochemische Zeitschrift, Vol 49 (1913) pp. 335–369 (Translation by T.R.C. Boyde in FEBS Letters, vol 587 (2013) pp. 2712–2720)[3]
• Jobling, J. W., Flexner, S., Menten, M. L. Tumors of animals New York: Rockefeller Institute for Medical Research, 1910

• Timeline of women in science

• Some called her Miss Menten by Rebecca Skloot in Pittmed (University of Pittsburgh School of Medicine magazine), October 2000
• Johnson, Kenneth A.; Goody, Roger S. (October 2011). "The Original Michaelis Constant: Translation of the 1913 Michaelis-Menten Paper". Biochemistry. 50 (39): 8264–8269. doi:10.1021/bi201284u. PMC 3381512. PMID 21888353.