Proteins are found in all biological organisms and are involved in many processes within biological systems that include supporting biochemical reactions, transporting and storing chemical compounds, signalling information from other proteins, maintaining the structures of biological components (e.g. cells, tissues), converting chemical energy into mechanical energy causing muscular movement and generating immune responses to the harmful foreign bodies within the organism. The function that a protein assumes depends on its 3D structure. Therefore, protein structure determination is crucial for drug design and the study of diseases, such as Alzheimer’s and some forms of cancer, resulting from protein defects.

The main techniques involved in 3D protein structure determination are X-Ray crystallography and Nuclear Magnetic Resonance (NMR) spectroscopy. X-Ray crystallography is the more commonly used technique. However, it requires protein crystallisation, which is a very arduous process and may take months to happen, or might not occur at all. On the other hand, NMR Spectroscopy can be used to study a protein under almost physiological conditions. However, it is harder to automate NMR Spectroscopy experiments, when compared to X-Ray crystallography.

Back in 1958, British scientists John Kendrew and Max Perutz published the first high-resolution protein structures. The proteins concerned were myoglobin (an oxygen-storage protein) and haemoglobin (an oxygen-transporting protein). Kendrew and Perutz shared the 1962 Nobel Prize in chemistry for this work, which had been ongoing since 1937.

During the 1960s numerous new high-resolution protein structures were determined and the experimental techniques involved were highly improved. It is during this decade that ‘molecular biology’ attained full recognition as a field of study.

In the 1970s, the Protein Data Bank became established as a global repository for 3D protein structures. The latter transformed the manner in which proteins were collected and classified. During the 1980s, the production of large quantities of proteins from cloned genes became possible, drastically increasing the number of new protein structures determined.

At this point, the determination of protein structures started playing a crucial role in drug discovery through structure-based drug design. Development of synchrotron X-ray sources in the 1990s allowed protein structures to be determined in much shorter times and at even higher resolutions, while new technologies developed in the 2000s rendered protein structure determination faster and cheaper than any time before.

Currently, structural biologists are also developing computational methods to actually predict 3D structures. Investigating how the structure of a protein affects its function and its subsequent biomedical impact definitely adds to our current knowledge about our health.

In Malta, studies on various protein structures and function are performed at the Laboratory of Biochemistry and Protein Science, (Department of Physiology and Biochemistry, Faculty of Medicine and Surgery, University of Malta), headed by Prof. Gary Hunter and Dr Therese Hunter.

Did you know…

• The largest organ of the human body is the skin.

• The distinctive pink flamingo colour develops thanks to their selective diet, which primarily consists of organisms – such as shrimp and algae ­– high in pigments called carotenoids. These carotenoids are also the same pigments that cause shrimp to turn from grey to pink when we boil them.

• A red blood cell takes 20 seconds to circulate around the human body.

• The biomass of all bacteria on earth is more than all the plants and animals combined

• The biggest egg in the world is the ostrich egg. It could take as many as 30 chicken eggs to equal its volume and up to two hours to hard boil.

For more trivia: www.um.edu.mt/think

Sound bites

• In a new report, the US Government Accountability Office has made perfectly clear how outdated some government computer systems are. One of the most shocking is the Department of Defence Strategic Automated Command and Control System, which is used to control America’s nuclear arsenal. It is literally the system that could destroy the world. Oh, and it is so outdated that it still uses eight-inch floppy disks because it is a 1970s computing system.

• Summer is close by, as is the scorching heat. On September 13, 1922, the mercury in a thermometer soared to 57.8 degrees Celsius in El Azizia, Libya. Scientists say this is the hottest temperature ever recorded on the planet, though higher temperatures might have occurred in places where there are no measuring stations. Do not forget to put on your sunscreen.