Investigation of the organisation of the major proteins in bovine myelin membranes. Use of chemical probes and bifunctional crosslinking reagents.

Bovine myelin was incubated with a variety of bifunctional reagents and chemical probes. The use of a photosensitive hydrophobic compound, 1-azido-[125I]iodobenzene, led to the suggestion that the proteolipid protein is deeply intercalated into the hydrophobic milieu of the membrane, but did not support the contention that regions of the basic protein behave in a similar fashion. Crosslinking studies indicated that both polypeptides may be present in the membrane as homodimers and these dimers may be part of much larger assemblies. These results give rise to a somewhat different model for the structural organisation of myelin to that proposed earlier.