“Laughter is the best medicine - unless you are diabetic, then insulin comes pretty high on the list” – Jasper Carrott
Remember the medicine the doctor says your elderly grandparent has to take every now and then for diabetes sugar control? That medicine is insulin, one of the earliest success stories of the biopharmaceutical industry.
Insulin is a hormone or a signalling chemical which is produced in the beta cells of our pancreas. It regulates the levels of energy molecules like glucose in our blood by forcing the excess glucose to get absorbed into the liver, adipose tissue and skeletal muscles. The beta cells secrete insulin when there is high blood sugar level and don’t secrete anything when the sugar levels are low. The neighbours of beta cells are the alpha cells which do the opposite work of the beta cells by secreting the polar opposite of insulin, known as glucagon which promotes the release of stored sugars when sugar levels are low in blood.
The human insulin protein is made of 51 amino acids (the building blocks of proteins) and consists of an A chain and B chain which are linked together by disulphide bonds. It is 5808 times heavier than a hydrogen atom. Insulin was discovered way back in the early 20th century by a team of biologists at the University of Toronto and this discovery was recognized in the 1923 Nobel Prize for Physiology or Medicine. The entire sequence of amino acids which comprise insulin was first found out by the British biochemist Frederick Sanger for which he was awarded the Nobel Prize in Chemistry in 1958. The crystal structure of Insulin in the solid state was first discovered by the pioneering crystallographer and 1964 Nobel laureate in Chemistry Dorothy Crowfoot Hodgkin.
Purified insulin obtained from animals was the only known cure for treating diabetes for a long time. This was however difficult to come by in significant amounts and was inaccessible to much of the patient population. However, due to Sanger’s discovery of the Insulin structure, things began to change. insulin was first synthesized in the laboratories of Helmut Zahn and Panayotis Katsoyannis simultaneously in the 1960s. In 1978, genetically engineered human insulin was first synthesized using E. coli cells by biotechnologists Arthur Riggs and Keiichi Itakura of Beckman Research Institute and Herbert Boyer of Genentech. In 1982, Genentech went on to sell the first vials of biosynthetic human insulin under the brand name of “Humulin”. Today Insulin is produced either in genetically engineered yeast or E. coli cells. In India, Biocon is the main player of the insulin market.
Since its inception, insulin research has attracted people from diverse fields such as biology, chemistry, biochemistry, pharmaceutics, chemical engineering, biotechnology etc. The biochemists identified the structure while the molecular biologists pondered over how to get microbes to produce human insulin by tinkering with their genes. The cell biologists worked on how to culture those cells to get high yields and good quality of insulin while the biotechnologists designed the huge bioreactors required for production. The chemical engineers came up with and designed the separation strategy for fishing out insulin from the large amount of soup generated in the bioreactor. The analytical chemists checked the quality of the product while the pharmacists worked on various formulations for stabilizing the product.
The success story of Insulin in treating diabetes which is a major cause of concern in India due to the high number of cases recorded each year is heartening. The success was due to the team efforts and collaboration of many scientists and engineers who tackled chunks of the larger problem. Similar success stories are in the pipeline of the biopharmaceutical industry.
Keeping the importance of collaborative work between various disciplines for future successes in mind, the Institute of Chemical Technology, Matunga, Mumbai is organizing a biosimilars workshop during 29th November to 1stDecember,2018. This workshop will familiarize the participants on the challenges related to making life saving molecules such as Insulin and the newer molecules being targeted by the biopharmaceutical industry.
Be a part of the future success stories !!
Sai Vivek Prabhala, Final Year B Chem Engg., Department of Chemical Engineering, Institute of Chemical Technology, Mumbai