NZ scientist: We've got much to learn about the fabric of life

Otago University biochemist Dr Wayne Patrick says we need to challenge the status quo when it comes to understanding enzymes - the proteins vital to all life on Earth. Photo / ODT

An incredible process that could turn harmful gases into useful products like car tyres by engineering enzymes shows why scientists need to keep challenging our understanding of what are the proteins vital to all life on Earth.

That's the message from Otago University researchers, whose research has suggested the need for a fundamental rethink of the evolutionary path of enzymes.

Enzymes catalyse a vast array of biologically relevant chemical reactions even in the simplest living cells.

Biochemist Dr Wayne Patrick said people tended to imagine evolution as a slow and steady march from barely functional life forms in the primordial soup, towards a modern-day pinnacle of near perfection.

"When it comes to enzyme evolution, this is also the textbook version of the events occurring at the molecular level; a smooth and steady trajectory, from barely functional primordial catalysts to the highly active and specific enzymes that we observe today."

But upon closer examination, he said, the reality appeared quite different.

In an article appearing in the UK Journal of the Royal Society Interface, Dr Patrick, his PhD student Matilda Newton and their collaborator Professor Vic Arcus, summarise experimental data that challenges the prevailing thinking.

"We discuss examples in which enzymes have evolved with lightning speed - over years, rather than eons - and provide evidence that many enzymes were better catalysts in the ancient past than they are today," Dr Patrick said.

One example of extraordinarily rapid evolution is the emergence of enzymes that modern-day bacteria use to break down human-made antibiotics and pesticides.

"Studying the complexities of enzyme evolution not only provides fundamental knowledge about how life emerged from the primordial soup, but also gives insights into designing proteins with biomedical and biotechnological applications."

Dr Patrick and colleagues at the Department of Biochemistry's Laboratory for Enzyme Engineering and Evolution were currently pursuing such applications. Their work includes collaborating with leading biotechnology company LanzaTech, which has a microbe that can grow by using harmful gases from industrial plants such as steel mills and oil refineries.

The Otago researchers are engineering enzymes to put into this microbe so it can produce useful raw materials that would otherwise have to be made from petroleum.

This microbe would be used to produce chemicals from greenhouse gases that could be worth billions of dollars a year.

The two chemicals - butanone and 2-butanol - are at present produced from petroleum, which the chemistry industry is seeking to replace with a more sustainable source.

"This is a great example of the ways in which really fundamental research - carried out with a grant from the Marsden Fund - can translate into applied outcomes in unexpected ways," Dr Patrick said.