Contents

20 March 1987
Vol 235, Issue 4795

About The Cover

Domains of a synthetic molecular cleft. Regions of high polarity (red and blue) in the lining of the cleft combine with hydrophobic methyl groups (yellow) and an aromatic acridine nucleus (green). These domains provide surfaces for binding smaller molecules of complementary size, shape, and functionality in studies of molecular recognition. See page 1478. [W. C. Still, University of Pittsburgh, Pittsburgh, PA 15260]