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purified with phosphoglycerides, the typical lipids of the non-raft domain,
whereas MBP belonging to the raft and the hyper-raft domains was mainly
associated to glycosphingolipids and cholesterol.
What changes MBP distribution of MBP in the myelin membrane are
some post-translational modifications. For example, raft MBP is phos-
phorylated and non-raft MBP is methylated (DeBruin, Harauz, 2007).
Selective extraction of MBP demonstrates that MBP has different par-
titioning and, as a consequence, different roles in the myelin membrane.
Classic acid-extracted MBP is actually a mixture of MBP with high het-
erogeneity, and this might be the reason why the protein has been never
crystallized.
Incorporation of myelin basic protein in liposomes
made of myelin lipids
All our studies on the MBP extracted from the membrane within its
native lipid environment and purified with bound lipids indicate that the
protein is structured. All detergent-extracted, lipid-bound MBPs can
unfold following a denaturing treatment. Moreover, it can be affirmed
that the MBPs distributed in different membrane domains have been sub-
jected to different chemical modifications and have different structures
and functions.
On these grounds, MBP can no longer be seen as an IUP or as
a natively unfolded protein, but rather as a flexible, malleable and multi-
functional protein that can be adapted to different environments following
precise chemical modifications.
Time is now ripe for the study of MBP structure but restricting the
investigation to MBP extracted and purified from the different myelin
domains. However, since detergents have without doubt an influence on
protein structure, we suggest that MBP structure should be studied after
removal of the detergent used for its extraction and incorporation in the
original lipid mixture.
Therefore, we have tried to reconstitute the MBP in its original envi-
ronment, reincorporating the purified protein into liposomes made by the
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