Maude Leonora Menten (1879 - 1960) 300

Maud Leonora Menten (1879 – 1960) was a Canadian pathologist, biochemical researcher and physician.

Menten had a long and distinguished career at the University of Pittsburgh, from which she retired as Full Professor in 1950

As well as her work in the development of enzyme kinetics (Michaelis-Menten equation 1913), Menten made a number of other contributions as an experimental pathologist. Menten worked with Helen Manning on the distribution of potassium and chloride ions in nerve cells (1912); hyperglycaemic effects of Salmonella toxins (1925); the nature of vitamin C deficiency and the harmful effects that occur well before scurvy appears (1935); the electrophoretic mobility and sedimentation of different forms of haemoglobin (1944); a method for the histochemical detection of alkaline phosphatase (1944); investigation of the histochemical distribution of glycogen in kidneys (1951)

Menten not only excelled in biochemical research but was also an accomplished musician (clarinet); talented painter whose work was exhibited in galleries; and a gifted linguist speaking English, French, German, Italian, Russian, and Halkomelem (language of various First Nations peoples of the Pacific Northwest Coast)

  • Born 20 March 1879, Port Lambton, Canada
  • 1904 – BA, University of Toronto
  • 1904-1905 Demonstrator in physiology in the laboratory of Archibald MacCallum (1858-1934) – founder of the National Research Council of Canada.
  • 1907 – MB (bachelor of medicine) from the University of Toronto
  • 1907-1909 Fellow at the Rockefeller Institute for Medical Research studying the effect of radium on tumours with with Simon Flexner (1863-1946) and James Wesley Jobling (1876–1961)
  • 1909-1911 Research fellow, Western Reserve University, Cleveland studying Hydrogen ions in blood
  • 1911 – MD, University of Toronto; one of the first Canadian women to receive a medical doctorate in Canada. Physiology demonstrator in MacCallum’s laboratory.
  • 1912 – Research was Menten’s calling, but as a woman she was unable to pursue this further in Canada so she crossed the Atlantic to work with Leonor Michaelis (1875-1949) at the Hospital Am Urban, Berlin
  • 1913-1914 Research fellow, Western Reserve University, Cleveland studying Hydrogen ions in blood with George Crile (1864-1943)
  • 1916 – PhD in biochemistry, University of Chicago
  • 1918-1924 Faculty of the University of Pittsburgh School of Medicine; Demonstrator in pathology (1918); Assistant professor of pathology (1923)
  • 1925 – Associate professor of pathology, University of Pittsburgh School of Medicine
  • 1926-1950 Pathologist at the Children’s Hospital of Pittsburgh
  • 1949 – Professor of pathology, University of Pittsburgh School of Medicine
  • 1951-1954 British Columbia Medical Research Institute, Vancouver. Studying the nucleic acid content of the bone marrow of leukaemia patients, using normal and leukaemic mice as animal models
  • Canadian Medical Hall of Fame Laureate (1998)
  • Died 26 July 1960, Leamington, Canada

Medical Eponyms
Michaelis-Menten equation (1913)

The Michaelis-Menten equation used in textbooks today is derived from the 1903 publications and thesis of work of Victor Henri (1872-1940). This work was cited extensively and amplified and expanded by Michaelis and Menten in their 1913 publication in Biochemische Zietschrift. George Briggs and JBS Haldane in 1925 added the steady state assumption and simplified the final equation. Johnson and Goody provided the full translation and review of the original Michaelis-Menten paper in 2011

Michaelis and Menten studied the enzyme invertase, which breaks down complex sugars (sucrose) into simpler sugars (fructose and glucose). They found that the rate at which glucose and fructose appear depends on:

  1. the binding of sucrose to invertase (initial capture);
  2. the catalyzed chemical conversion of sucrose into simpler sugars; and
  3. the unbinding of fructose and glucose from invertase (final release). 
Michaelis-Menten equation enzyme substrate product

Enzyme (E) binds reversibly to its substrate (S), creating an enzyme-substrate (ES) complex. This complex breaks down, forming the product (P) and regenerating the free enzyme (E).

According to Michaelis and Menten (1913) the substrate concentration was to be regarded as an important factor controlling the velocity of an enzyme reaction. The velocity (v) of a reaction is related to the substrate concentration (S) by the Michaelis-Menten equation where Vmax is the maximum velocity of the reaction when the enzyme is saturated with substrate. The term Km is the Michaelis constant which indicates an enzyme’s affinity for its substrate

Michaelis-Menten equation

Key Medical Contributions

1925 – Helen Manning and Menten observed that guinea pigs and rabbits infected with Salmonella and other bacterial infections developed hyperglycaemia. They studied the paratyphoid in rabbits to understand the relationship between the hyperglycaemia and the endotoxins produced by the bacteria. They concluded (1925) that bacterial endotoxins cause a depletion of glycogen reserves. Later confirmed by McCallum in 1973

1944 – Menten and colleagues used sedimentation and electrophoresis to distinguish between haemoglobin variants in 1944 well before the ‘more famous’ and oft quoted work of Linus Pauling (1901-1994) and his work on sickle cell disease (1949). Menten et al proposed that ‘adult and fetal hemoglobins might be differentiated by electrophoretic mobilities, if the variation exists in the protein part of the molecule’

1944 – Histochemical detection of alkaline phosphatase in the kidney. Alkaline phosphatase is widely distributed in different animal tissues, and its importance as a histochemical marker led Menten et al (1944) to develop an azo dye method for the detection of alkaline phosphatase in the kidney, based on detection of the alcoholic product of hydrolysis of the phosphate ester used as the substrate. The Menten-Junge-Green method effectively opened up the field of enzyme histochemistry.

Major Publications

  • Name: Maud usually misspelled as Maude;
  • Middle name: Leonora but often written as Lenora or Lenore. Birth certificate has no middle initial, this has led to speculation that Leonora is in tribute to Leonor Michaelis; however, her first article published in 1906 already has the middle initial and derivation is likely as a family name.
  • Surname: Menten is most commonly misspelled as Menton. Journal articles and even major medical textbooks still list the wrong eponymous term as “Michaelis-Menton equation”




Dr Charlotte Baker LITFL

Studied at Univerisity of Cambridge - BA MB BChir. British doctor working in emergency medicine in Perth, Australia. Special interests include primary care and emergency medicine.

BA MA (Oxon) MBChB (Edin) FACEM FFSEM. Emergency physician, Sir Charles Gairdner Hospital.  Passion for rugby; medical history; medical education; and asynchronous learning #FOAMed evangelist. Co-founder and CTO of Life in the Fast lane | Eponyms | Books | Twitter |

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