Protein Structures: The Cooperative Substructure of Protein Molecules; Y. Bai, S.W. Englander. Protein Folding: Approaches to the Determination of More Accurate Crossrelaxation Rates and the Effects of Improved Distance Constraints on Protein Solution Structures; G.C. Hoogstraten, J.L. Markley. Protein Interactions: How Conventional Antigens and Superantigens Interact with the Human MHC Class II Molecule HLADR1; T. Jardetzky. Nucleic Acids and Nucleic Acid-Protein Interactions: Stimulating the Dynamics of the DNA Double Helix in Solution; M. Hirshberg, M. Levitt. Membranes: Applications of Multidimensional Solidstate NMR Spectroscopy to Membrane Proteins; A. Ramamoorthy, et al. Carbohydrate Structure: Conformation, Mobility, and Function of the N-linked Glycan in the Adhesion Domain of Human CD2; G. Wagner, et al. Abstracts from Course: Protein Structures Abstracts: Solution Structure of the ETS-domain from Murine Ets1: A Winged-helix-turn-helix Motif; L.W. Donaldson. Protein Interactions Abstracts: Designing Mutant Hemoglobins; M. Madrid, et al. Nucleic Acids and Nucleic Acid-Protein Interactions Abstracts: A Study on the Dynamics of a DNA Binding Protein; L.M. Horstink, et al. Poster Abstracts. 55 additional articles. Index.

From within complex structures of organisms and cells down to the molecular level, biological processes all involve movement. Muscular fibers slide on each other to activate the muscle, as polymerases do along nucleic acids for replicating and transcribing the genetic material. Cells move and organize themselves into organs by recognizing each other through macromolecular surface-specific interactions. These recognition processes involve the mu tual adaptation of structures that rely on their flexibility. All sorts of conformational changes occur in proteins involved in through-membrane signal transmission, showing another aspect of the flexibility of these macromolecules. The movement and flexibility are inscribed in the polymeric nature of essential biological macromolecules such as proteins and nucleic acids. For instance, the well-defined structures formed by the long protein chain are held together by weak noncovalent interac tions that design a complex potential well in which the protein floats, permanently fluctuating between several micro- or macroconformations in a wide range of frequencies and ampli tudes. The inherent mobility of biomolecular edifices may be crucial to the adaptation of their structures to particular functions. Progress in methods for investigating macromolecular structures and dynamics make this hypothesis not only attractive but more and more testable.