UNDER DEVELOPMENT: Layman's Guide
What follows is an attempt to explain my research in layman's terms, beginning with the Techniques used.
Techniques
Structural biology is the science of studying the three-dimensional structures of biological molecules such as nucleic acids (DNA, RNA etc.) and proteins (e.g. insulin, hemoglobin, collagen etc.). These molecules are made up of many atoms (mainly carbon, hydrogen, oxygen, nitrogren, sulfur and phosphorus) which are bonded together in a particular 3D arrangement. The goal of the structural biologist is to determine the specific arrangement of atoms in a particular molecule and to use this information to explain or predict its function and how that relates to other molecules. [ANALOGY: Different types of buildings]
In order to view the atomic structure of a molecule, one must effectively magnify it up to a human scale. (e.g. one trillion times magnification: an atom is 1-2 trillionths of a centimetre in size (1-2 x 10^-10m) and to investigate a molecular structure we need to be able to view its atoms at 1-2 centimetres size).
The magnification by microscopes, even electron microscopes is not powerful enough, only allowing magnification by about one billion-fold, so we have to use other, less direct, techniques.
X-ray crystallography is a technique that relies on the ability of pure samples of a given molecule to form crystals, where many copies of the same molecule line up in a particular repeating arrangement [ANALOGY: a brick wall]. Crystals composed of sucrose can be found in your sugar bowl and sodium chloride crystals in your saltcellar. Even proteins containing thousands of atoms can be made to crystallise under optimised chemical conditions.
If you shine an X-ray through an electron cloud, the electrons scatter the X-ray. Atoms have electron clouds around their nucleus, so by shining an X-ray through a crystal, we can observe how it is scattered by the atoms in the crystal, depending on the arrangement of the atoms. [ANALOGY: This is like shining a powerful torch at a chandelier and recording where the scattered spots of light are found on the wall. If you couldn't see the chandelier, you might still be able to work out the arrangement of its glass components by analysing the pattern caused by its scattered light. A more accurate, but abstract analogy is if a group of people stand at one end of a swimming pool and each drop a marble into the pool. By measuring the position at which ripples hit the other end of the pool, one can calculate where the marbles were originally dropped.] Once we have measured this X-ray data, we can use a number of complicated experimental and computational techniques to determine the positions of the dense electron coulds around each atom in the structure, and thus, the positions of the atoms.
Once we have the molecular structure we can analyse it, work out which parts of it are responsible for which functions, design small molecules which inhibit it's function (drugs) and many more things.
(c) 2005 Charlie Bond