Report of the 1999 Ewald prize presntation
Professor G.N.Ramachandran
The Ewald Prize consists of a medal, a certificate and an award of $30,000
and is presented once every three years during the triennial International
Congresses of Crystallography. This year the fifth recipient of the prize
became Professor G.N.Ramachandran for his outstanding contributions in the
area of anomalous scattering and its use in the solution of the phase
problem in the analysis of the structure of fibres, collagen in particular,
and for his fundamental work on the conformation of macromolecular
structures by means of the 'Ramachandran plot'. Sadly, ill health prevented
Professor Ramachandran collecting the prize in person and so it was accepted
on his behalf by Professor M.Vijayan, Bangalore who delivered a lecture
entitled
"X-Ray Crystallography and macromolecular Conformation".
G.N.Ramachandran was born in 1922 in Kerala, a southern Indian state; he
gained a first degree in Madras and then went on to gain a Masters degree in
electrical engineering in 1940, working with Professor Raman at Bangalore
who persuaded him to change his field to work on optics and the topography
of diamond. In 1951 he came to England to work with Lawrence Bragg and
W.A.Wooster in Cambridge where he gained another PhD before returning
briefly to Bangalore, then moving on to Madras in 1952 where he established
the Department of Physics. Almost twenty years later he moved back to
Bangalore to found the Centre for Structural Biology in 1971.
In 1952/53 J.D.Bernal visited him in Madras and suggested the structure of collagen was one of the great unsolved problems, so Ramachandran set to work modelling collagen from fibre diffraction. He spotted errors in the current models of the day and in 1954 arrived at his triple helix model which had two hydrogen-bonds per unit; Crick had independently deduced one hydrogen-bond per unit more recent single crystal work showed the correct result to be 1.5 hydrogen-bonds per unit, a happy compromise between these two proposals. Following on from this work Ramachandran became interested in a more general identification of the conformation possibilities available to peptide bonds, calculating with his students the steric hindrance regions involved. From this he devised a way of mapping the conformational space in two dimensions by plotting the two torsional angles against each other; this produced two distinct regions populated by a-helices and b-sheets. This map became well known as the Ramachandran plot which even today remains a well-used validation tool for proposed structural models and statistical studies. In the 1970s his interest moved to problems of mathematical logic
and he was still active in 1990 when he proposed a new method of structural analysis.
During the lecture Prof Vijayan used slides made from Ramachandran's original papers, apologising for not projecting the coloured slides of structures which are common in 1999, but also pointing out that we could appreciate Ramachandran's efforts better if we saw the structures in the form with which he worked at the time. Thus Prof. Vijayan paid tribute to the distinguished work of Ramachandran, neatly summarising his career as a tale of two cities: Madras and Bangalore.
Paul Barnes,
Birkbeck College London
1. The following selected references to Ramachandran's work in the fields of
structural biology and crystallography were kindly written out by hand by
Prof M.Vijayan later; please let the Editor know of any errors in the
transcription below.
2. The Indian Academy of Sciences plan to publish a book in his honour later this year.
"Perspectives in Structural Biology. A volume in honour of G.N.Ramachandran"
edited by M.Vijayan, N.Yathindra, A.S.Kolaskar
It is intended to be a window on modern structural biology and a showcase of Indian effort in this area, with articles contributed by leading scientists, including two Nobel Laureates.
Distributors Orient Longman Ltd, price $35.00
ISBN 81 7371 254 9 PB 760pp 180 x 240 mm email [email protected]
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