Welcome to the LEARN section of our site. Here we hope to give students and the public a clear understanding about our field, and illustrate its successful practice in Victoria.
What is Proteomics?
You've probably heard the term "genome", which refers to all the genes in an individual. And "genomics", which means to study the genome, in whole or large part. Well much the same thing goes for proteins. In its simplest form, "proteome" means all the proteins in an individual (i.e. all the proteins encoded by all its genes) and "proteomics" is the study of as many of those proteins as practicable. Sound logical? No surprise then to learn the term proteome was first coined by a bunch of Australians (Marc Wilkins and colleagues, Macquarie University, Sydney, 1994).
With proteins some extra considerations apply. The proteins making up your hair are clearly different from those in your eyes, even though they all come from the same genome. So "proteome" must be linked to the particular thing under consideration – whether it is a person, an organ such as kidney, a type of cell, or part of a cell such as the mitochondrion. Also, proteomes are dynamic, varying with your age, state of health and the time of day for example. Bottom line – the term proteome needs to be qualified (e.g. the proteome of kidney from a healthy, male, asian child).
Proteomics has come about through major technological advances over the past 15 years or so. Whereas protein chemists of the past were limited technically to studying just a few proteins during their whole careers, nowadays we can access thousands of proteins at once. One key advance was the development of specialised instruments called mass spectrometers, which enable proteins to be characterised by very accurate weighing.
The genomics revolution has provided other crucial advances. Foremost, gene libraries obtained from genome (DNA) sequencing have provided a huge shortcut for identifying proteins by mass spectrometry. Improved computing and the development of "bioinformatics" software for exploring this biological information have also been pivotal to progress.
Proteomics provides scientists with a variety of key benefits. Studying numerous proteins at once provides a much more meaningful, or "holistic", view of whats going on than in the old days when only a few identified proteins could be monitored at once. Thus, proteomic findings are likely to be closer to physiological truth than before. Diagnostic power is also vastly improved when based on findings from multiple proteins. Being protein based, proteomics also conveys information not available from gene-based approaches – many attributes of proteins, such as their quantity and location in a cell, are not predictable from gene information.
Medically this sort of information is crucial because most drugs work on proteins, not genes. However, with these great attractions of proteomics come several headaches – proteins are much more numerous and generally trickier to work with than genes. The protein world also does not have a tool equivalent to that which kicked off the genomics revolution, the polymerase chain reaction (PCR) method for amplifying DNA. As a consequence, only the more abundant of proteins tend to be accessible to proteomics currently.