The past decade has seen a revolution in the application of X-rays to biology. Biochemists have made enormous strides in being able to identify, isolate and/or synthesize biologically important materials such as proteins and viruses. Although most proteins are very large molecules, typically 100,000 atoms or more, it is now routine practice to grow high quality protein crystals and use synchrotron X-ray diffraction to fully determine their atomic structure.

Knowing their structures, scientists hope to uncover how certain biological materials cause physical ailments and diseases. This rather young field of protein crystallography has had notable successes at CHESS, include the first determination of the structure of the mammalian rhinovirus HRV14 by the group of Prof. M. Rossmann (Purdue) (HRV14 is one of the agents responsible for causing the common cold) and recent work by Prof. E. Arnold (Rutgers) and his group to determine the structure of the HIV Reverse Transcriptase type 1.

Knowing a structure is just the first step towards understanding how proteins and viruses function. Once the chemical structure of a virus is know, scientists need to reveal its function and design a drug to inhibit the disease causing agent. This process of "structure-based drug design" is an emerging field that has already established itself as a nation-wide (and world-wide) program dependent on access to synchrotron X-ray facilities such as CHESS.

Scientists at CHESS have helped pioneer new methods to advance the field of protein crystallography. Biological materials can be fragile or may be damaged by the high-intensity X-ray beams. Specimens made from proteins are exposed to a number of hazards, including the threat of being ingested by microorganisms or being damaged by X-ray photons (in some ways similar to getting a sunburn). To counter these effects, protein crystals are usually suspended in a drop of fluid (see photo above) and frozen in a liquid nitrogen cold stream. These (and other) techniques are being developed at CHESS by a research group called MacCHESS (short for Macromolecular crystallography at CHESS). This group, headed by Professor Dan Thiel (Biochemistry, Cornell), builds and supports facilities at CHESS that are used on a routine basis to determine the structure of living materials.