Honouring the rockstars of science

This year’s rockstars of science have paved the way for the better understanding of our universe and existence. From the discovery of the Higgs boson to chemical computation, their Nobels are well-deserved, reckons C Sivaram.

Pioneering work in every field continues to happen every day. And to honour the best of those is what the Nobel Prize is all about. In  the field of science, this year, there are all together eight winners. This year’s Nobel Prize for physics is shared between Peter Higgs and Francois Englert for the pioneering work done 50 years ago, elucidating how elementary particles involved in various fundamental interactions could acquire masses. They invoked a massive self-interacting scalar field (now called the Higgs field) pervading all space, the excitations of the field being the Higgs boson whose couplings to various particles determines their masses.

 The idea was used by Salam and Weinberg to explain why, although the photon is mass-less (mediating infinite range of electromagnetic interactions), the bosons mediating the weak interactions acquire mass (by the Higgs mechanism) and are short-range. This enables the unification of weak and electromagnetic interactions and predicts the masses of the W and Z bosons (mediating weak interactions). These bosons were discovered in 1983 at CERN leading to the award of Nobel Prize to Carlo Rubbic and Van Vaerden. Salam Weinberg and Glashow shared the 1979 Physics Nobel. This success led to the standard model of particle physics with the predicted parameters matching experimental values to unprecedented accuracy.

The chemistry prize was shared by Martin Karplus, Michael Levitt and Ariel Warshel for their seminal work in computational chemistry which has found universal application in analysing multi-action chemical reactions underlying phenomena from photosynthesis, enzymatic processes in cells and industrial chemistry. Even earlier, in crystallography for example, how atoms were positioned in molecules and how they could be rearranged in different ways involved much computation (leading to earlier Nobel Prizes). Even large molecules could be studied with the methods developed.

But these techniques involved atoms in a state of rest. These were snapshots of static configurations. However, to simulate chemical reactions taking place over millisecond or shorter time scales required use of quantum physics. In this connection, the Karplus equation (used in nuclear magnetic resonance) was developed. Meanwhile, Levitt and Warshel developed versatile computer programmes (based on classical models) to deal with all types of molecules.

 While modeling retinal, a molecule embedded in the retina of the eye, Karplus and Warshel combined the quantum and classical computational schemes. When the retina is struck by photons, the free electrons in retinal acquire energy altering the molecular shape. This is the primary stage leading to human vision. Their discovery has led to much better understanding of how chemical processes occur in diverse systems using the universality of the methods developed. Industrial chemistry could mimic some of these complex biological reactions (for e.g., to make more efficient use of solar energy mimicking photosynthesis or produce complex products). The techniques developed would contribute to such developments.

Medical marvels

This year’s Physiology or Medicine prize was shared between James Rothman, Randy Schekman and Thomas Sudhof. They figured out how biological cells organise and transport the several molecules required for their functioning.The work was done 30 to 40 years ago and involved different aspects of the mechanisms by which complex molecules like hormones, enzymes, neurotransmitters are in motion around cells in so called ‘vesicles’ which are tiny bubbles of fatty membrane. The puzzle was how these vesicles are transported to the right part of the cell at the right time to enable the myriads of chemical reactions (involved in various bodily functions) to occur and switch off.

Using yeast as his model organism, Schekman worked out the underlying genetic basis for the vesicle manoeuvres. Rothman uncovered the complex protein structures that enable vesicles to fuse with their targets, thus shedding their cargo of molecules which they transported!

Thomas Sudhof worked on neurotransmitters underlying nerve cell activity and the cellular signals that enable the vesicles to release the transmitters precisely at the right place. These cell transport mechanisms are exquisitely fine tuned and errors can cause problems like diabetes, immune and nervous disorders etc. Schekman also devised a genetic screen to identify genes regulating intracellular transport.

Rothman developed a novel approach using invitro-reconstitution to unravel events in vesicle transport budding and fusion, and with related biochemical studies proposed models as to how vesicle fusion occurs with the required specificity (sequential steps of synaptic docking, activation and fusion are involved).

Their work has elucidated essential machinery in routing of important molecular cargo in cells and is applicable to all diverse organisms from yeast to man!