THE ELASTICITY OF SPIDERS WEBS IS DUE TO WATER-INDUCED MOBILITY AT A MOLECULAR-LEVEL

C-13 nuclear magnetic resonance (NMR) spectroscopy of intact webs from the common garden spider Araneus diadematus has been used to demonstrate that: (I) water retention is an important role for the viscid coating of capture thread; (II) the elasticity of capture thread results from water-induced mobility at a molecular level (III) the organization and composition of structural and capture thread are different, even in the absence of coating; and (IV) glycoproteins may have a more important presence and structural role than previously realized. Different C-13-labelling patterns of webs were achieved by feeding spiders either with [C-13]glucose or with [C-13]amino acids.