Figure 5.

Visualization of surface-bound macromolecules. The upper image is part of a central slice of a three-dimensional reconstruction of a negatively stained collagen fibril, showing macromolecules bound at preferred axial locations along the fibril. The arrow shows the molecular polarity of the fibril. The gallery shows views of 18 individual macromolecules that were bound to N-telopeptides (N-telo), C-telopeptides (C-telo), and the gap zone. Nine macromolecules are shown for each location. Note the doughnut (ring-shaped) structure at the N-telopeptides and the tadpole-shaped molecule bound to the C-telopeptides. The macromolecules bound to the gap zone were smaller and more conspicuous than those bound to the telopeptides.