In a recent discussion with some friends the topic drifted to Indian Nobel Prize winners. Almost everyone seemed to know about C.V Raman, or Rabrindranath Tagore and about Subramanian Chandershekhar and also their contributions. But very few of us knew much about Dr Hargobind Khorana and his contributions towards Science. In today’s VERITAS we will try to correct this situation.
Dr Hargobind Khorana was born in 1922 at Raipur, Punjab ( this is now in Pakistan). He was born in a poor family. His father was a “patwari”
in the village. A “patwari” is an agrigulture tax collector. This is a post that is still common in Punjab villages. He was the youngest in the family of 5 children. Hargobind Khorana attended D.A.V high school in Multan. Later he studied in Punjab University at Lahore and got the MSc degree. He got a scholarship to study in England. He joined the University of Liverpool and got the Phd degree in 1948. IN 1949 he returned to India. He tried desperately to search for a job but he could not find one. He returned to England and joined Cambridge.
At Cambridge Hargobind Khorana became interested in proteins and nucleic acids(DNA and RNA). He moved to Canada in 1952 and joined the University of British Columbia. In 1968 Khorana received the Nobel Prize in Physiology and Medicine along with Nirenberg and Holley. They were awarded the Nobel Prize for their research which led to deciphering of the Genetic Code and helped understand its function in protein synthesis.
Lets understand this in more detail. In 1944 Avery showed that genes are made up of Nucleic acids. Both DNA and RNA are composed of 4 nucleotide bases. DNA is composed of adenine(A), Guanine(G), Cytosine(C) and Thymine(T). DNA is composed of strings of these bases. So a DNA strand may look like AATGGGTTACCC etc. Nirenberg was the first to show that each set of 3 bases like AAA or GGG etc forms an amino acid. He formed an artificial DNA by constructing a string of a single repeating base. So Nirenberg showed how DNA/RNA is composed of repeating bases. Khorana developed this work independently and decipered the codes for several known amino acids. He discovered for example that the amino acid Glycine was GGA etc. He did this by constructing giant nucleic acids( giant DNA and RNA) with complicated base strings. Holley succeeded in preparing something known as transfer-RNA and determined its exact structure.
Transfer-RNA is a special type of nucleic acid. It has the ability of reading genetic code from somewhere else and transforming it to form a protein.
So Hargobind Khorana was one of the scientists who succeeded in understanding the alphabet which is used to create DNA and RNA. He also managed to create DNA and RNA in his laboratory. So Hargobind Khorana is one of the pioneers of Genetic Engineering.
Hargobind Khorana is still doing active research. I went to his webpage in the “faculty and research” section of MIT’s chemistry department. He is currently doing research on molecules that act as receptors of light in the eye- Rhodopsin, 11-cis-retinal, all-trans retinal( See VERITAS: Light and Life Part II, May 12, 2005 for details on these molecules and the bio-chemical mechanism of sight).
Go, wondrous creature! mount where Science guides:
Go, measure earth, weigh air, and state the tides:
Instruct the planets in what orbs to run,
Correct old time and regulate the Sun;