Computer models of the human immunoglobulins shape and segmental flexibility

At present there is interest in the design and deployment of engineered biosensor molecules. Antibodies are the most versatile of the naturally occurring biosensors and it is important to understand their mechanical properties and the ways in which they can interact with their natural ligands. Two dimensional representations are clearly inadequate, and three dimensional representations are too complicated to manipulate except as numerical abstractions in computers. Recent improvements in computer graphics allow these coordinate matrices to be seen and more easily comprehended, and interactive programs permit the modification and reassembly of molecular fragments. The models which result have distinct advantages both over those of lower resolution, and those showing every atom, which are limited to the few fragments(2-5) or mutant molecules for which the X-ray crystallographic coordinates are known. In this review Richard Pumphrey describes the shape and flexibility of immunoglobulin molecules in relation to the three dimensional structure.