• DOI:10.1038/88544
• Corpus ID: 7231304

G.N. Ramachandran

@article{Subramanian2001GNR,
  title={G.N. Ramachandran},
  author={Easwara Subramanian},
  journal={Nature Structural Biology},
  year={2001},
  volume={8},
  pages={489-491}
}

• E. Subramanian
• Published 1 June 2001
• Chemistry
• Nature Structural Biology

nature structural biology • volume 8 number 6 • june 2001 489 G.N. Ramachandran, an outstanding figure in the field of protein structure, passed away at the age of 78, on April 7, 2001, in Chennai (the erstwhile city of Madras), India. Ramachandran (G.N.R. or Ram to his friends and associates) was the founder of the ‘Madras school’ of conformational analysis of biopolymers. His discovery of the triple helical structure of collagen in 1955 and his analysis of the allowed conformations of proteins through the use of the ‘Ramachandran plot’ rank among the most outstanding contributions in structural biology, along with Pauling’s description of the α-helix and Watson and Crick’s discovery of the double helical structure of DNA. G.N. Ramachandran (‘G’ stands for Gopalasamudram, his native town, and ‘N’ stands for Narayana Iyer, the name of his father) was born on October 8, 1922, in a small town not far from Cochin on the southwestern coast of India. His father was a Professor of Mathematics at a local college and thus had considerable influence in shaping Ram’s interest in mathematics. After completing his school years, Ramachandran graduated in 1942 as the top-ranking student in the B.Sc. (Honors) Physics course of the University of Madras. In 1942, Ramachandran joined the Master’s program in Electrical Engineering at the Indian Institute of Science at Bangalore but was soon brought into the Physics stream by the head of the Physics Department, Sir C.V. Raman, who was awarded the 1930 Nobel Prize in Physics for his discovery of the Raman effect. (Until Raman discovered this effect, it was generally believed that scattered light can have its frequency shifted only towards the red end of the spectrum, towards lesser energy. Raman discovered shifts in the frequency of scattered light towards the blue end of the spectrum, towards greater energy, violating common sense and conventional wisdom. Raman’s discovery was one of the important tools that dethroned the deterministic world of classical physics and launched the probabilistic world of quantum physics.) Under the guidance of Raman, Ramachandran continued in Physics, did his post-graduate research in the areas of optics and X-ray topography Ramachandran became a professor of physics at the University of Madras at the age of 29. The generous assistance and hospitable administrative support provided by Sir A.L. Mudaliar enabled Ramachandran to set up a fully equipped modern X-ray crystallographic laboratory at Madras. In the beginning, Ramachandran had trouble deciding which projects were worthy of attention. Pauling’s lectures at Cambridge on the structure of polypeptide chains were still fresh in his mind, as were Pauling’s publications on models of the α-helix and β-sheet structures. He knew that he wanted to work on biological problems, but the directions that he finally took were influenced by Professor J.D. Bernal who paid a visit to Madras during late 1952 and early 1953. Ramachandran asked Bernal for advice regarding suitable projects, and Bernal suggested that Ramachandran could work on the structure of collagen for which no satisfactory models had been proposed. Ramachandran therefore directed his attention to solving the structure of collagen. Using collagen samples from kangaroo tail tendon, and assisted by Gopinath Kartha who was his first post-doc, Ramachandran produced X-ray diffraction patterns from the collagen fibers. Using these data, and armed with relevant physicochemical data, they started building ball-and-stick models of the collagen structure. Those efforts culminated in a paper1 published in Nature in 1954 on the structure of collagen. Their proposed model for the collagen structure consisted of three parallel left-handed helical polypeptide chains standing side-by-side and packed together in a hexagonal array. Each helix had 32 symmetry, hence 3 residues per turn of the helix. Every third residue in each chain was a glycine, and all the glycines were located inside, facing the common central axis. Subsequently, Ramachandran and Kartha revised the model in light of more detailed studies of the fiber diffraction patterns. In the revised model, the number of residues per turn became 3.3, so that each of the 3 parallel left-handed helical chains was made to coil around the common central axis in a right-handed way, giving rise to the now famous coiled G.N. Ramachandran