The science of pretty much everything

By Associate Professor Allan Blackman

This article was orignally published in the Otago Daily Times on Tuesday 12 October 2004.

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What is chemistry? This is probably not a question the general public has spent much time agonising over.

At the risk of generalizing, mention of the word “chemistry” probably engenders visions among many of test tubes, bubbling liquids, noxious gases, unanticipated explosions and the like, all of which are overseen by half-crazed wild-haired men (sadly, always men) in white coats.

I think I can safely say that chemists are probably primarily viewed as people who make chemicals.

But chemistry is so much more than this, and nowhere is this better exemplified than in the award of this year’s Nobel Prize in chemistry to three scientists, none of whom would describe themselves as chemists.

Aaron Ciechanover and Avram Hershko, of the Institute for Research in the Medical Sciences at the Israel Institute of Technology, and Irwin Rose, of the College of Medicine at the University of California at Irvine, were jointly awarded the 2004 Nobel Prize in chemistry this month “for the discovery of ubiquitin-mediated protein degradation”. Ciechanover and Hershko have PhD degrees in medicine, while Rose has a PhD in biochemistry. Their prizewinning work dates to the start of the 1980s, when Ciechanover and Hershko spent time in Rose’s laboratory at the Fox Chase Cancer Centre in Philadelphia, in the United States, and concerns the way human cells dispose of unwanted proteins.

All human cells contain a huge number of proteins, large molecules which are constructed from “nature’s building blocks”, the amino acids, and which carry out a large number of processes necessary for life.

While historically, most attention had been paid to figuring out how cells manufacture proteins, relatively little was known about the ways in which proteins were degraded in cells.

This year’s laureates were the first to show that proteins within the cell are marked for destruction through the attachment of a molecule called ubiquitin, originally so-called because it is found in many tissues and organisms. When numerous molecules of ubiquitin have attached to the protein, it is delivered to a constituent of the cell called a proteasome, which essentially chews up the protein, while leaving the ubiquitin molecules free to bind to further proteins.

This might sound somewhat arcane and academic, but such processes are vitally important in the human body. Interference with the levels of ubiquitin in the cell has been shown to be a vital factor in certain types of cancer, where a viral infection tricks the cell into destroying a particular protein that suppresses tumours.

Cystic fibrosis also appears to be related to protein breakdown in the cell, where lack of an amino acid called phenylalanine within a particular protein results in it being destroyed, rather than carrying out its intended function in the cell wall.

Thus, an understanding of how cells deal with unwanted proteins is crucial and this year’s award is recognition of that.

I must admit that most of the preceding paragraphs describe concepts which are outside my, and indeed most chemists’, fields of expertise. But everything I’ve described is chemistry, and this only serves to show that even the fundamental processes that govern life itself are simply chemistry. It truly is a ubiquitous science.

As a sad footnote, I note the passing this month of the New Zealand-born Nobel Prize winner Maurice Wilkins, who, along with Jim Watson and the recently deceased Francis Crick, unravelled the structure of DNA. His work quite literally changed the world.