The zinc environment in Langmuir-Blodgett phospholipid multi-layers.

The Zinc environment of a system formed by Langmuir-Blodgett phospholipid multi-layers is investigated by employing X-ray absorption spectroscopy. A comparative analysis of the Extended X-ray Absorption Fine Structure and Near Edge regions of the X-ray absorption spectra at the Zinc K-edge, in presence and in absence of the Myelin Basic Protein, clearly indicates that Zinc ions are bound to the heads of the phospholipidic molecules, while the presence of Myelin Basic Protein induces a visible distorsion of the geometry of the Zinc environment. These findings represent a first important step in understanding the interplay among the lipids of the myelin sheath, Myelin Basic Protein and Zinc, as Langmuir-Blodgett phospholipid multi-layers represent a valuable model for the multilamellar structure of the membrane surrounding the nerve axon.