Christian de Duve

Christian René Marie Joseph, Viscount de Duve (2 October 1917 – 4 May 2013) was a Nobel Prize-winning Belgian

De Duve was born of an estate agent Alphonse de Duve and wife Madeleine Pungs in the village of Thames Ditton, near London. His parents fled Belgium at the outbreak of the First World War. After the war in 1920, at age three, he and his family returned to Belgium. He was a precocious boy, always the best student (primus perpetuus as he recalled) in school, except for one year when he was pronounced "out of competition" to give chance to other students.^[2]

He was educated by the

In March 1947 de Duve joined the faculty of the medical school of the Catholic University of Leuven teaching physiological chemistry. In 1951 he became full professor. In 1960, Detlev Bronk, the then president of the Rockfeller Institute (what is now Rockefeller University) of New York City, met him at Brussels and offered him professorship and a laboratory. The rector of Leuven, afraid of entirely losing de Duve, made a compromise over dinner that de Duve would still be under part-time appointment with a relief from teaching and conducting examinations. The rector and Bronk made an agreement which would initially last for five years. The official implementation was in 1962, and de Duve simultaneously headed the research laboratories at Leuven and at Rockefeller University, dividing his time between New York and Leuven.^[21]

In 1969, the Catholic University of Leuven was contentiously

De Duve was first to hypothesise that the production of insulin (which decreased blood sugar levels), stimulated the uptake of glucose in the liver; he also proposed that a mechanism was in-place to balance the productions of insulin and glucagon in order to maintain normal blood sugar level, (see homeostasis). This idea was much disputed at the time, but his rediscovery of glucagon confirmed his theses. In 1953 he experimentally demonstrated that glucagon did influence the production (and thus the uptake) of glucose.^[45][46]

Discovery of lysosome

Christian de Duve and his team continued studying the insulin mechanism-of-action in liver cells, focusing on the enzyme

This was the moment of serendipitous discovery. To estimate the exact enzyme activity, the team adopted a procedure using a standardised enzyme acid phosphatase; but they were finding the activity was unexpectedly low—quite low, i.e., some 10% of the expected value. Then one day they measured the enzyme activity of some purified cell fractions that had been stored for five days. To their surprise the enzyme activity was increased back to that of the fresh sample; and similar results were replicated every time the procedure was repeated. This led to the hypothesis that some sort of barrier restricted rapid access of the enzyme to its substrate, so that the enzymes were able to diffuse only after a period of time. They described the barrier as membrane-like—a "saclike structure surrounded by a membrane and containing acid phosphatase."^[50][51]

An unrelated enzyme (of the cell fractionation procedure) had come from membranous fractions that were known to be cell organelles. In 1955, de Duve named them "lysosomes" to reflect their digestive properties.

Serendipity followed de Duve for another major discovery. After the confirmation of lysosome, de Duve's team was troubled by the presence (in the rat liver cell fraction) of the enzyme urate oxidase. De Duve thought it was not a lysosome because it is not an acid hydrolase, typical of lysosomal enzymes; still, it had similar distribution as the enzyme acid phosphatase. Further, in 1960 he found other enzymes (such as catalase and D-amino acid oxidase), that were similarly distributed in the cell fraction—and it was then thought that these were mitochondrial enzymes.^[54] (W. Bernhard and C. Rouillier had described such extra-mitochondrial organelles as microbodies, and believed that they were precursors to mitochondria.)^[55] de Duve noted the three enzymes exhibited similar chemical properties and were similar to those of other peroxide-producing oxidases.^[56]

De Duve was skeptical of referring to the new-found enzymes as microbodies because, as he noted, "too little is known of their enzyme complement and of their role in the physiology of the liver cells to substantiate a proposal at the present time".^[57] He suggested that these enzymes belonged to the same cell organelle, but one different from previously known organelles.^[23] But, as strong evidences were still lacking, he did not publish his hypothesis. In 1955 his team demonstrated similar cell fractions with same biochemical properties from the ciliated protozoan Tetrahymena pyriformis; thus, it was indicated that the particles were undescribed cell organelles unrelated to mitochondria. He presented his discovery at a meeting of the American Society for Cell Biology in 1955,^[58] and formally published in 1966, creating the name peroxisomes for the organelles as they are involved in peroxidase reactions.^[59] In 1968 he achieved the first large-scale preparation of peroxisomes, confirming that l-α hydroxyacid oxidase, d-amino acid oxidase, and catalase were all the unique enzymes of peroxisomes.^[60][61]

De Duve and his team went on to show that peroxisomes play important metabolic roles, including the

De Duve's work has contributed to the emerging consensus towards accepting the

His family (von Duve) came from Hanover and settled in Belgium after the Battle of Waterloo.
De Duve married Janine Herman on 30 September 1943. Together they had had two sons, one of whom is noted art professor Thierry de Duve, and two daughters.

Janine died in 2008, aged 86.^[19]

Death

De Duve died on 4 May 2013, at his home in Nethen, Belgium, aged 95. He decided to end his life by legal euthanasia, performed by two doctors and in the presence of his four children. He had been long suffering from cancer and atrial fibrillation, and his health problems were exacerbated by a recent fall in his home.^{[75][14][15][76]}

De Duve was cremated as he had willed, and his ashes were distributed among family members and friends.

Awards and honours

De Duve won the

De Duve founded a multidisciplinary biomedical research institute at Université catholique de Louvain in 1974, originally named the International Institute of Cellular and Molecular Pathology (ICP).[83] He remained its president until 1991. On his 80th birthday in 1997 it was renamed the Christian de Duve Institute of Cellular Pathology. In 2005 its name was further contracted to simply the de Duve Institute.^[84]

De Duve was one of the founding members of the Belgian Society of Biochemistry and Molecular Biology, established on 15 September 1951.^[85]

De Duve is remembered as an inventor of important scientific terminology. He coined the word lysosome in 1955, peroxisome in 1966, and autophagy, endocytosis, and exocytosis in one instance at the Ciba Foundation Symposium on Lysosomes held in London during 12–14 February 1963, while he, "was in a word-coining mood."^[23][86]

De Duve's life, including his work resulting in a Nobel Prize, and his passion for biology is the subject of a documentary film Portrait of a Nobel Prize: Christian de Duve (Portrait de Nobel : Christian de Duve), directed by Aurélie Wijnants. It was first aired on Eurochannel in 2012.^[87]

References

External links

• Christian de Duve on Nobelprize.org

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