Leonor Michaelis
Encyclopedia
Leonor Michaelis was a German biochemist
Biochemist
Biochemists are scientists who are trained in biochemistry. Typical biochemists study chemical processes and chemical transformations in living organisms. The prefix of "bio" in "biochemist" can be understood as a fusion of "biological chemist."-Role:...

, physical chemist, and physician
Physician
A physician is a health care provider who practices the profession of medicine, which is concerned with promoting, maintaining or restoring human health through the study, diagnosis, and treatment of disease, injury and other physical and mental impairments...

, known primarily for his work with Maud Menten
Maud Menten
Maud Leonora Menten was a Canadian medical scientist who made significant contributions to enzyme kinetics and histochemistry. Her name is associated with the famous Michaelis-Menten equation in biochemistry.Maud Menten was born in Port Lambton, Ontario and studied medicine at the University of...

 on enzyme kinetics
Enzyme kinetics
Enzyme kinetics is the study of the chemical reactions that are catalysed by enzymes. In enzyme kinetics, the reaction rate is measured and the effects of varying the conditions of the reaction investigated...

 and Michaelis-Menten kinetics
Michaelis-Menten kinetics
In biochemistry, Michaelis–Menten kinetics is one of the simplest and best-known models of enzyme kinetics. It is named after German biochemist Leonor Michaelis and Canadian physician Maud Menten. The model takes the form of an equation describing the rate of enzymatic reactions, by relating...

 in 1913.

Early life and education

Leonor Michaelis was born in Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 on January 16, 1875 and graduated from the humanistic Koellnisches Gymnasium in 1893 after passing the Abiturienten Examen. It was here that Michaelis’ interest in physics and chemistry was first sparked as he was encouraged by his teachers to utilize the relatively unused laboratories at his school.

With concerns about the financial stability of a pure scientist, he commenced his study of medicine at Berlin University in 1893. Among his instructors were Emil du Bois-Reymond
Emil du Bois-Reymond
Emil du Bois-Reymond was a German physician and physiologist, the discoverer of nerve action potential, and the father of experimental electrophysiology.-Life:...

 for physiology
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

, Emil Fischer
Emil Fischer
Emil Fischer may refer to:* Emil Fischer , German dramatic basso* Franz Joseph Emil Fischer , German chemist, worked with oil and coal* Hermann Emil Fischer , German Nobel laureate in chemistry...

 for chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

, and Oskar Hertwig
Oskar Hertwig
Oscar Hertwig was a German zoologist and professor, who also wrote about the theory of evolution circa 1916, over 55 years after Charles Darwin's book The Origin of Species...

 for histology
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...

 and embryology
Embryology
Embryology is a science which is about the development of an embryo from the fertilization of the ovum to the fetus stage...

.

During his time at Berlin University, Michaelis worked in the lab of Oskar Hertwig
Oskar Hertwig
Oscar Hertwig was a German zoologist and professor, who also wrote about the theory of evolution circa 1916, over 55 years after Charles Darwin's book The Origin of Species...

, even receiving prize for a paper on the histology of milk secretion. Michaelis’s doctoral thesis work on cleavage determination in frog eggs led him to write a textbook on embryology. Through his work at Hertwig’s lab, Michaelis came to know Paul Ehrlich
Paul Ehrlich
Paul Ehrlich was a German scientist in the fields of hematology, immunology, and chemotherapy, and Nobel laureate. He is noted for curing syphilis and for his research in autoimmunity, calling it "horror autotoxicus"...

 and his work on blood cytology
Cytology
Cytology means "the study of cells".Cytology is that branch of life science, which deals with the study of cells in terms of structure, function and chemistry.Based on usage it can refer to:...

; he worked as Ehrlich’s private research assistant from 1898 to 1899.

He passed his physician’s examination in 1896 in Freiburg
Freiburg
Freiburg im Breisgau is a city in Baden-Württemberg, Germany. In the extreme south-west of the country, it straddles the Dreisam river, at the foot of the Schlossberg. Historically, the city has acted as the hub of the Breisgau region on the western edge of the Black Forest in the Upper Rhine Plain...

, and then moved to Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, where he received his doctorate in 1897. After receiving his medical degree, Michaelis worked as a private research assistant to Moritz Litten
Moritz Litten
Moritz Litten was a German physician who was a native of Berlin. He was a son-in-law to pathologist Ludwig Traube ....

 (1899–1902) and for Ernst Viktor von Leyden
Ernst Viktor von Leyden
Ernst Viktor von Leyden was a German internist from Danzig.Leyden studied medicine at the Friedrich-Wilhelms-Institut in Berlin, and was a pupil of Johann Lukas Schönlein and Ludwig Traube . He was a medical professor at several universities, including Königsberg, Strassburg and Berlin...

 (1902–1906).

Life and work

From 1900 to 1904, Michaelis continued his study of clinical medicine at a municipal hospital in Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, where he found time to establish a chemical laboratory.
He attained the position of Privatdocent at the University of Berlin in 1903. In 1905 he accepted a position as director of the bacteriology lab in Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

s Charité
Charité
The Charité - Universitätsmedizin Berlin is the medical school for both the Humboldt University and the Free University of Berlin. After the merger with their fourth campus in 2003, the Charité is one of the largest university hospitals in Europe....

 hospital, becoming Professor extraordinary at Berlin University in 1908. In 1914 he published a paper suggesting that Emil Abderhalden
Emil Abderhalden
Emil Abderhalden was a Swiss biochemist and physiologist. His main findings, though disputed already in the 1920s, were not finally rejected until the late 1990s. Whether his misleading findings were based on fraud or simply the result of a lack of scientific rigor remains unclear...

's notorious pregnancy tests could not be reproduced, a paper which fatally compromised Michaelis' position as an academic in Germany (L. Michaelis, L von Lagermark, Deutsche Med. Wochenschr. 1914, 7, 316-319). In 1922, Michaelis moved to the Medical School of the University of Nagoya
Nagoya University
Nagoya University is one of the most prestigious universities in Japan. It can be seen in the several rankings such as shown below.-General Rankings:...

 (Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

) as Professor of biochemistry
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

, becoming one of the first foreign professors at a Japanese university, bringing with him several documents, apparatuses and chemicals from Germany. His research in Japan focused on potentiometric measurements and the cellular membrane.

In 1926, he moved to Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...

 in Baltimore, Maryland as resident lecturer in medical research
Research
Research can be defined as the scientific search for knowledge, or as any systematic investigation, to establish novel facts, solve new or existing problems, prove new ideas, or develop new theories, usually using a scientific method...

 and in 1929 to the Rockefeller Institute of Medical Research in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

, where he retired in 1941.

Besides his role in the formulation of the famous Michaelis-Menten
Michaelis-Menten kinetics
In biochemistry, Michaelis–Menten kinetics is one of the simplest and best-known models of enzyme kinetics. It is named after German biochemist Leonor Michaelis and Canadian physician Maud Menten. The model takes the form of an equation describing the rate of enzymatic reactions, by relating...

 equation (1913) he discovered Janus green
Janus green
Janus Green B is a basic dye and vital stain used in histology. It is also used to stain mitochondria supravitally.The indicator Janus Green B changes colour according to the amount of oxygen present.*Oxygen present: Indicator oxidised to blue colour...

 as a supravital stain for mitochondria and the Michaelis-Gutmann body in urinary tract infection
Urinary tract infection
A urinary tract infection is a bacterial infection that affects any part of the urinary tract. Symptoms include frequent feeling and/or need to urinate, pain during urination, and cloudy urine. The main causal agent is Escherichia coli...

s (1902) and found that thioglycolic acid
Thioglycolic acid
Thioglycolic acid is the organic compound HSCH2CO2H. It contains both a thiol and a carboxylic acid. It is a clear liquid with a strong unpleasant odor...

 could dissolve keratin
Keratin
Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...

, a discovery that would come to have several implications in the cosmetic industry, including the permanent wave
Permanent wave
A permanent wave, commonly called a perm, involves the use of chemicals to break and reform the bonds of the hair. The hair is washed and wrapped on a perm rod and waving lotion is applied with a base. This solution creates a chemical reaction that softens the inner structure of the hair by...

.

Honors

Michaelis was a Harvey Lecturer in 1924 and a Sigma Xi Lecturer in 1946. He was elected to be a Fellow of the American Association for the Advancement of Science in 1929, a member of the National Academy of Sciences in 1943. In 1945, he received an honorary LL.D. from the University of California, Los Angeles
University of California, Los Angeles
The University of California, Los Angeles is a public research university located in the Westwood neighborhood of Los Angeles, California, USA. It was founded in 1919 as the "Southern Branch" of the University of California and is the second oldest of the ten campuses...

.
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