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Bibudhendra Sarkar Recipient “Order of Canada” | |
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Born | August 2, 1935 |
Nationality | Canadian |
Citizenship | Canada |
Alma mater | Calcutta University Banaras Hindu University University of Southern California |
Known for | Inventor of Menkes disease treatment by copper-histidine |
Spouse | Dipti Dutt (d. 1985) |
Children | 2 |
Scientific career | |
Fields |
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Institutions | Hospital For Sick Children and University of Toronto |
Thesis | Studies on the transport, metabolism and chemistry of iron-sugar chelates (1964) |
Doctoral advisor | Paul Saltman |
Bibudhendra (Amu) Sarkar CM (born August 2, 1935) is a Canadian biochemist best known for his research on copper-histidine in human blood, leading to the first treatments for Menkes disease. He served as head of the Division of Biochemistry Research at the Sick Kids Research Institute in Toronto from 1990-2002, where he established the Department of Structural Biology Research in 1990. [1]
Bibudhendra Sarkar was born on August 2, 1935 in Kushtia, Bengal, British India (now Bangladesh). [2] [3] His father, Surendra Nath Sarkar, was a lawyer and mother, Sucheta Sarkar (née Chaki), a homemaker who died when he was one year old. [2] He attended Kushtia Mission School, a Catholic school for his kindergarten and primary education. [2]
Following the Partition of India in 1947, his family was forced to leave behind everything and migrated to Calcutta. [2] He studied in City College School and City College, Kolkata. [2] He obtained his Matriculation and Intermediate Science Certification from the University of Calcutta. [3] [4] He then enrolled in the Banaras Hindu University, Uttar Pradesh [2] where he received B. Pharm and M. Pharm degrees specializing in the chemistry of natural products. [2] During his studies in BHU he was a regular summer student in the Central Drug Research Institute in Lucknow where he was mentored by Manojit Mohan Dhar. [2] Dhar encouraged Sarkar to do his graduate studies in the USA or Europe. [2] Sarkar then travelled to the USA to do his graduate studies in biochemistry in the University of Southern California, under the supervision of Paul Saltman. Sarkar was influenced by several scientists while at USC: Sydney Benson in chemical kinetics, Arthur Adamson in physical chemistry and Bo Malmström in metal-activated enzyme chemistry. [2] Sarkar graduated with a PhD in biochemistry in 1964. [2] [5]
In early 1964 Sarkar was presenting his PhD work at the Federation of American Societies for Experimental Biology (FASEB) meeting in Chicago where Andrew Sass-Kortsak, a clinician specialist in Wilson’s disease at the Hospital for Sick Children in Toronto, Canada came to listen. [2] [6] Sass-Kortsak was leading the Genetic Metabolic Program of the Hospital for Sick Children and was looking for a young basic scientist to join in his program. [2] [6] Sass-Kortsak offered Sarkar a Staff Scientist’s position in the Genetic Metabolic Research Program with start-up funds and his own laboratory in a newly built wing in SickKids. [2] Soon thereafter he was cross-appointed to the Department of Biochemistry at the University of Toronto. [1]
Sarkar began attending Grand Rounds with Sass-Kortsak and went to the wards to visit Wilson’s disease patients. [2] Because of his interest in the biophysical aspects of metal protein interactions and metal transport, Sarkar’s research turned to metal-related diseases. He pioneered multidisciplinary research in SickKids in association with Sass-Kortsak by crossing the boundaries between basic science and clinical medicine and creating a collaborative environment in SickKids. [6] In 1990 he was appointed Head of the Division of Biochemistry Research in SickKids. [1]
Sarkar discovered copper-histidine in human blood. [7] He invented the treatment of Menkes disease by copper-histidine. [8] [9] He discovered the amino terminal Cu (II)- and Ni (II)- binding (ATCUN) motif of proteins. [10] [11] This motif has been used to cleave DNA, [12] [13] [14] applied as a paramagnetic probe [15] and used to kill Ehrlich cells. [16] His laboratory identified and characterized the six copper-binding sites of copper-ATPase [17] that is defective in Wilson’s disease. [18] He pioneered the development of metalloproteomics, a subdiscipline of proteomics that attempts to identify and characterize all metal-associated proteins in a well-defined system. [19] [20] [21] [22] [23] [24] He also contributed to global health research in Bangladesh, India, Nepal, and Myanmar, where tens of thousands of people are exposed to naturally occurring arsenic and other toxic metals in drinking water from underground wells [25] [26] [27] [28] [29] [30] [31] [32] [33] Sarkar is considered a pioneer in establishing inorganic biochemistry through his research in the early 1960s. He organized the first international meeting of Biological Inorganic Chemistry in the Board Room of the Hospital for Sick Children in 1972. [34] This initiative was followed by the 56th Nobel Symposium in Inorganic Biochemistry held in Sweden under the auspices of the Nobel Foundation in 1982 where Sarkar was an invited speaker. [35] He has published extensively in scientific journals, organized many series of international symposia on metals and genetics, edited several books on metals in biology, genetics, and environment. [36] [37] [38] [39] He was a founding member as well as a member of the first Editorial Board of Metallomics published by the Royal Society of Chemistry, UK. [40]
Sarkar discovered copper-histidine in human blood in 1966 and recognized it as a biological form by which copper, an essential element to sustain life, is transported in blood. [7] In 1976, Sarkar proposed that a baby with Menkes disease receive copper-histidine via subcutaneous injection. [6] This was the world’s first Menkes patient to receive copper-histidine therapy. [6] [7] [8] [41] Children with this disease are now living longer and reaching adulthood with copper-histidine treatment. [8] [9] [41] [42] [43] Sarkar did not patent copper-histidine; he intended that it be readily available to Menkes patients at a reasonable cost. [6] [41] The formulation and detailed compounding procedure for the preparation of copper-histidine is freely available by SickKids Pharmacy to physicians and hospital pharmacies around the world upon request. [6] [41] Sarkar also helped make copper-histidine formulation for Menkes disease in other countries including NIH Clinical Center, Bethesda, Md. USA, [44] India, [45] and Mexico. [46]
Sarkar solved the structure of the copper(II)-histidine molecule used for the treatment of Menkes disease. [47] He discovered the ATCUN (Amino terminal Cu(II), Ni(II) binding) motif of proteins and peptides. [10] [11]
Sarkar’s laboratory identified six copper-binding sites of Wilson’s disease ATPase with all six copper atoms binding ATPase in +1-oxidation state. [17] Based on nuclear magnetic resonance (NMR) studies, Sarkar’s team proposed that copper transfer to and between the N-terminal domains of the Wilson ATPase occurs via protein interactions that are facilitated by the flexibility of the linkers and the motional freedom of the domains with respect to each other. [18]
Sarkar along with his colleague Eve Roberts, a hepatologist and Wilson’s disease specialist, pioneered the development of metalloproteomics. [20] [21] [22] [23] [24] He first presented the concept and findings of metalloproetomics relating to copper in 2002. [19] [20]
Sarkar led a team of international scientists investigating naturally occurring arsenic and other toxic metals throughout South- and Southeast Asia. In his early research in Bangladesh, Sarkar identified a small child with advanced signs of arsenic poisoning, an observation that motivated extensive research in this region. [48] [49] [50] Discovery Canada Television produced an hour-long documentary focusing on Sarkar’s work on this devastating health crisis in Bangladesh. [26] [27] Sarkar’s team discovered that arsenic is not the only toxic metal contaminating the groundwater; other toxic metals such as, manganese, lead, chromium, and uranium are also present in groundwater. They produced heat maps of arsenic and other toxic metals in Bangladesh and West Bengal (India) groundwater, identifying areas where contamination is of special concern. [28] [29] Their investigation was further extended to the neighboring country of Myanmar (Burma), which has a similar geology, and where they found high concentrations of many of the same toxic metals in groundwater. [30] Sarkar’s team also carried out field work in Kathmandu, Nepal in 2015. [31] In addition, the team called for the WHO to re-evaluate its guidelines for many toxic substances in drinking water based on their health hazards. [32] Sarkar’s team stressed that multiple metal contamination of groundwater is an issue of global concern, and the risks may be further magnified by climate change. [33]
Sarkar organized and chaired the first international meeting of Inorganic Biochemistry in the Board Room of SickKids with 35 participants in 1972 [34] which included among others, R J P Williams (Oxford), Gerhard Schrauzer (University of California, San Diego), David R. Williams (Saint Andrews University, UK), David A Brown (University College Dublin) and Barry Lever (York University). To acknowledge this new discipline the 56th Nobel Symposium introducing Inorganic Biochemistry was held in Sweden under the auspices of the Nobel Foundation in 1982 where Sarkar was an invited speaker. [35] He organized various series of Symposia on Metals and Genetics beginning in 1994 and edited several books on metals in biology, metal-related diseases, and metals in the environment. [36] [37] [38] [39] He was a member of the committee to establish terminology relating to -omics and metals under the auspices of the International Union of Pure and Applied Chemistry (IUPAC). [51] He was a founding member as well as a member of the first Editorial Board of Metallomics published by the Royal Society of Chemistry, UK. [40]
He was married to Dipti Sarkar (née Dutt) (b. 1944 – d. 1985), an Indian classical dancer, choreographer, and historian. [52] He has a son and a daughter. [52]
Arsenic is a chemical element with the symbol As and the atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is a notoriously toxic heavy metal. It occurs naturally in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. It has various allotropes, but only the grey form, which has a metallic appearance, is important to industry.
Metalloprotein is a generic term for a protein that contains a metal ion cofactor. A large proportion of all proteins are part of this category. For instance, at least 1000 human proteins contain zinc-binding protein domains although there may be up to 3000 human zinc metalloproteins.
Metallothionein (MT) is a family of cysteine-rich, low molecular weight proteins. They are localized to the membrane of the Golgi apparatus. MTs have the capacity to bind both physiological and xenobiotic heavy metals through the thiol group of its cysteine residues, which represent nearly 30% of its constituent amino acid residues.
Plastocyanin is a copper-containing protein that mediates electron-transfer. It is found in a variety of plants, where it participates in photosynthesis. The protein is a prototype of the blue copper proteins, a family of intensely blue-colored metalloproteins. Specifically, it falls into the group of small type I blue copper proteins called "cupredoxins".
Ceruloplasmin is a ferroxidase enzyme that in humans is encoded by the CP gene.
Dimercaprol, also called British anti-Lewisite (BAL), is a medication used to treat acute poisoning by arsenic, mercury, gold, and lead. It may also be used for antimony, thallium, or bismuth poisoning, although the evidence for those uses is not very strong. It is given by injection into a muscle.
Bioinorganic chemistry is a field that examines the role of metals in biology. Bioinorganic chemistry includes the study of both natural phenomena such as the behavior of metalloproteins as well as artificially introduced metals, including those that are non-essential, in medicine and toxicology. Many biological processes such as respiration depend upon molecules that fall within the realm of inorganic chemistry. The discipline also includes the study of inorganic models or mimics that imitate the behaviour of metalloproteins.
ATP7A, also known as Menkes' protein (MNK), is a copper-transporting P-type ATPase which uses the energy arising from ATP hydrolysis to transport Cu(I) across cell membranes. The ATP7A protein is a transmembrane protein and is expressed in the intestine and all tissues except liver. In the intestine, ATP7A regulates Cu(I) absorption in the human body by transporting Cu(I) from the small intestine into the blood. In other tissues, ATP7A shuttles between the Golgi apparatus and the cell membrane to maintain proper Cu(I) concentrations in the cell and provides certain enzymes with Cu(I). The X-linked, inherited, lethal genetic disorder of the ATP7A gene causes Menkes disease, a copper deficiency resulting in early childhood death.
Copper proteins are proteins that contain one or more copper ions as prosthetic groups. Copper proteins are found in all forms of air-breathing life. These proteins are usually associated with electron-transfer with or without the involvement of oxygen (O2). Some organisms even use copper proteins to carry oxygen instead of iron proteins. A prominent copper protein in humans is in cytochrome c oxidase (cco). This enzyme cco mediates the controlled combustion that produces ATP. Other copper proteins include some superoxide dismutases used in defense against free radicals, peptidyl-α-monooxygenase for the production of hormones, and tyrosinase, which affects skin pigmentation.
Catechol oxidase is a copper oxidase that contains a type 3 di-copper cofactor and catalyzes the oxidation of ortho-diphenols into ortho-quinones coupled with the reduction of molecular oxygen to water. It is present in a variety of species of plants and fungi including Ipomoea batatas and Camellia sinensis. Metalloenzymes with type 3 copper centers are characterized by their ability to reversibly bind dioxygen at ambient conditions. In plants, catechol oxidase plays a key role in enzymatic browning by catalyzing the oxidation of catechol to o-quinone in the presence of oxygen, which can rapidly polymerize to form the melanin that grants damaged fruits their dark brown coloration.
Metal toxicity or metal poisoning is the toxic effect of certain metals in certain forms and doses on life. Some metals are toxic when they form poisonous soluble compounds. Certain metals have no biological role, i.e. are not essential minerals, or are toxic when in a certain form. In the case of lead, any measurable amount may have negative health effects. It is often thought that only heavy metals can be toxic, but lighter metals such as beryllium and lithium may also be in certain circumstances. Not all heavy metals are particularly toxic, and some are essential, such as iron. The definition may also include trace elements when abnormally high doses may be toxic. An option for treatment of metal poisoning may be chelation therapy, a technique involving the administration of chelation agents to remove metals from the body.
ATOX1 is a copper metallochaperone protein that is encoded by the ATOX1 gene in humans. In mammals, ATOX1 plays a key role in copper homeostasis as it delivers copper from the cytosol to transporters ATP7A and ATP7B. Homologous proteins are found in a wide variety of eukaryotes, including Saccharomyces cerevisiae as ATX1, and all contain a conserved metal binding domain.
Copper toxicity is a type of metal poisoning caused by an excess of copper in the body. Copperiedus could occur from consuming excess copper salts, but most commonly it is the result of the genetic condition Wilson's disease and Menke's disease, which are associated with mismanaged transport and storage of copper ions. Copper is essential to human health as it is a component of many proteins. But hypercupremia can lead to copper toxicity if it persists and rises high enough.
Copper is an essential trace element that is vital to the health of all living things. In humans, copper is essential to the proper functioning of organs and metabolic processes. Also, in humans, copper helps maintain the nervous system, immune system, brain development, and activates genes, as well as assisting in the production of connective tissues, blood vessels, and energy. The human body has complex homeostatic mechanisms which attempt to ensure a constant supply of available copper, while eliminating excess copper whenever this occurs. However, like all essential elements and nutrients, too much or too little nutritional ingestion of copper can result in a corresponding condition of copper excess or deficiency in the body, each of which has its own unique set of adverse health effects.
Arsenic biochemistry refers to biochemical processes that can use arsenic or its compounds, such as arsenate. Arsenic is a moderately abundant element in Earth's crust, and although many arsenic compounds are often considered highly toxic to most life, a wide variety of organoarsenic compounds are produced biologically and various organic and inorganic arsenic compounds are metabolized by numerous organisms. This pattern is general for other related elements, including selenium, which can exhibit both beneficial and deleterious effects. Arsenic biochemistry has become topical since many toxic arsenic compounds are found in some aquifers, potentially affecting many millions of people via biochemical processes.
Vincent L. Pecoraro, professor at the University of Michigan, is a researcher in bioinorganic chemistry and inorganic chemistry. He is a specialist in the chemistry and biochemistry of manganese, vanadium, and metallacrown chemistry. He is a fellow of the American Association for the Advancement of Science
Wilson disease protein (WND), also known as ATP7B protein, is a copper-transporting P-type ATPase which is encoded by the ATP7B gene. The ATP7B protein is located in the trans-Golgi network of the liver and brain and balances the copper level in the body by excreting excess copper into bile and plasma. Genetic disorder of the ATP7B gene may cause Wilson's disease, a disease in which copper accumulates in tissues, leading to neurological or psychiatric issues and liver diseases.
Katherine J. Franz is the chair of the department of chemistry at Duke University. She studies metal ion coordination in biological systems and looks to use the insight to manage species such as copper and iron. Franz was awarded the American Chemical Society Award for Encouraging Women into Careers in the Chemical Sciences.
Deborah Beth Zamble was a Canadian chemist and Canada Research Chair in Biological Chemistry at the University of Toronto. Her research considered how bacteria processed metal nutrients.
Metallopeptides are peptides that contain one or more metal ions in their structure. This specific type of peptide are, just like metalloproteins, metallofoldamers. And very similar to metalloproteins, metallopeptide's functionality is attibuted through the contained metal ion cofactor. These short structured peptides are often employed to develop mimics of metalloproteins and systems similar to artificial metalloenzymes.