THE 3D-STRUCTURE OF A NATURAL INHIBITOR OF CELL-ADHESION MOLECULE EXPRESSION

The three-dimensional structure of cyclopeptolide HUN-7293, a naturall y-occurring inhibitor of cell adhesion molecule expression, has been d etermined from nuclear magnetic resonance data recorded in solution an d from X-ray diffraction analysis of single crystals. The backbone con formation of HCN-7293 is characterized by two cis-peptide bonds in bot h the solution and crystalline state, Differences between the solution and crystal structure are visible for the orientation of some side ch ains and the strength of two transannular hydrogen bonds. Such structu ral information helps to provide insight into the molecular architectu re of HUN-7293 on the atomic level and opens the way for structure-bas ed modifications of this novel inhibitor of cell adhesion molecule exp ression.