After almost a decade of studying and analysing proteins I’ve often found myself trying to explain to people “Why proteins?” What’s all the fuss about?
I recently came across this video produced for the laboratory of Professor Albert Heck at Utrecht University and the Netherlands Proteomics Centre. For me it provides a perfect glimpse into the world of proteins at work.
Proteins really are nature’s greatest creation. They’re life’s essential building blocks and the reason every one of us is capable of functioning on this planet. The versatility of these super molecules allows them to provide vital roles from our heads to our toes, and everything in-between. From the precise combination of proteins that are expressed in neurons, the haemoglobin that carries oxygen throughout our body, the array of enzymes that convert food into energy to the antibodies that protect us from pathogens. Collectively proteins can be used to catalyze thousands of different chemical reactions, all essential to life. Look beyond the simple human, throughout all of nature’s living wonders, proteins play a fundamental role; from the hard protection provided by a tortoise shell to the softness of the most delicate duck feather.
It’s not all good news; proteins can also be amongst the most deadly substances. Take botulinum toxin, a neurotoxic bacterium protein, the most toxic substance known to mankind. Most worryingly, it is the proteins already resident in the body which can cause the most harm. Take the major prion protein (PrP) and its scrapie isoform, for example, which causes numerous cognitive disorders and neurodegenerative diseases. Indeed proteopathies make up some of the most devastating diseases, and protein abundance and/or activational changes often facilitate the development of diseases such as cancer.
The good news is, the ability to study these proteins allows us to learn more and develop effective treatments to alleviate the burden of these diseases. Often it is proteins themselves that represent the most effective treatments today.
Protein therapeutics, protein engineering and biotherapeutics in general have revolutionized contemporary medicine, with antibody-based drugs arising as the largest and fastest growing class of protein therapeutics. Proteins can be incredibly complex molecules and can pose analytical challenges. Protein digestion is an essential tool to unravel the structure and function of theses amazingly versatile molecules.
Protein digestion is a fundamental aspect of characterizing proteins. This particular step is renowned for being time consuming and prone to variability. Imagine how excited I was recently to hear that protein digestion can be performed in under an hour with new digest kits; allowing proteins to be studied in the most comprehensive way, revealing their primary sequence.
Specific chemicals or enzymes can be used to chop proteins up into their characteristic peptides. Peptides are well suited to analysis by mass spectrometry. The unique mass of peptides provides a finger print which can be used to identify an individual protein (peptide mass fingerprinting). Within the mass spectrometer peptides can be further fragmented into their constituent amino acids, this reveals the precise amino acid sequence of each peptide, and thus the protein (find out more in our Peptide Mapping Learning Center). This type of analysis is called peptide mapping and is critically important in biotherapeutic discovery, development and bioproduction, where it’s necessary to confirm protein therapeutic quality.
The vista created by these essential building blocks of life is awe inspiring and looks set to become even more so, thanks to protein biotherapeutics.