At Home in the Cold
By Christopher P. Garnham, PhD
...All the hard work I put in had finally paid off. I was looking at something nobody else in the world had ever seen.
In most freezing environments on Earth, life not only persists – it thrives.
Ice-laden polar oceans, whose temperatures reach down to -1.9ºC, abound with species of fish impervious to the frigidity. The sub-polar land masses and snowcapped mountains, where temperatures drop below -50ºC, are home to many species of insects. How can these organisms survive such harsh conditions? In one word: antifreeze – the proteinaceous kind forged by the intense selective pressures of a freezing environment.
Antifreeze proteins (AFPs) are specifically capable of halting ice growth, and their evolution has allowed numerous species to expand into environments previously inaccessible. Typically, uncontrolled ice growth within an organism will result in its death. AFPs prevent ice growth by irreversibly bonding to the surface of ice crystals. this adsorption lowers the freezing point of a solution, which lowers the freezing point of the organism, therefore enhancing sub-zero survival.
AFPs are found not just in fish and insects, but in organisms including plants, bacteria, and fungi. Indeed, new AFPs are continually being discovered, and a number of these discoveries are made in the lab where I conduct my research – Dr. Peter Davies’ lab in the Department of Biochemistry. The primary focus of my PhD research has been the characterization of an AFP produced by an Antarctic bacterium.
I’ll never forget the first time I saw my protein at the atomic level, using a technique termed X-ray crystallography. All the hard work I put in had finally paid off. I was looking at something nobody else in the world had ever seen. The structure of my protein explained how it functions at the molecular level in particular, and more importantly, how all AFPs might function at the molecular level in general.
Being a fledgling scientist is not the world’s most glamorous job. However, there is no substitute for the feeling you get when you make a discovery that produces new knowledge. It’s addictive, and makes you want to come back for more.
In 2011, to celebrate the 10th Anniversary of the Canada Research Chairs (CRC) program, Queen’s University Vice-Principal (Research) launched a writing contest for current graduate students working with CRCs at Queen’s. Both masters and doctoral students were encouraged to submit entries. The contest sought to showcase the research of a Queen’s CRC through engaging stories that highlighted the successes of students’ research experience and demonstrated the research’s benefits to society. This is an abridged version of one of the winning stories.