Abstract
The molecular and supramolecular structure of the tectorial membrane (TM) was studied by transmission electron microscopy (TEM). Collagen (type A) fibrils in the TM were found associated with proteoglycans (PGs) and type B fibrils. Most PGs were orthogonally oriented and attached D-periodically to collagen fibrils. Computer averaged projections of PG particles and linear aggregates of PGs in crystalline arrays, stained with Cuprolinic blue, showed an elongated, electron-dense structure 50-65 nm in length and 10 nm in width. Image analysis of type B fibrils showed that they are constructed of globular domains arranged with a periodicity of 12-14 nm. Each globular domain contains two thin 'arms', extended in opposite directions, which contact the 'arms' of adjacent fibrils. Numerous type B fibrils were found between collagen fibrils. They are attached to adjacent collagen fibrils by the 'arms' of their globular domains. An association of type B fibrils and PGs with collagen seems to result in the local ordered arrangement of the TM matrix. A hypothetical model of the TM matrix supramolecular structure is presented.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 107-118 |
| Number of pages | 12 |
| Journal | Hearing Research |
| Volume | 110 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Aug 1997 |
Bibliographical note
Funding Information:This research was supported by a grant from the NIDCD. The authors thank Daniel Swartz for his critical reading of the manuscript and for the computer-drawn TM model.
Keywords
- Collagen
- Proteoglycan
- Tectorial membrane
- Thin fibril
- Transmission electron microscopy