title: Orientational ordering of carotenoids in myelin membranes resolved by polarized Raman microspectroscopy.
abstract: We study orientational ordering of membrane compounds in the myelinated nerve fiber by means of polarized Raman microspectroscopy. The theory of orientational distribution functions was adapted to live-cell measurements. The obtained orientational distribution functions of carotenoids and lipid acyl chain clearly indicated a predominantly radial-like orientation in membranes of the myelin. Two-dimensional Raman images, made under optimal polarization of incident laser beam, corroborated the proposed carotenoid orientation within the bilayer. Experimental data suggested the tilted orientation of both carotenoid polyenic and lipid acyl chains. The values of maximum tilt angles were similar, with possible implication of carotenoid-induced ordering effect on lipid acyl chains, and hence change of myelin membrane properties. This study stages carotenoids of the nerve as possible mediators of excitation and leverages underlying activity-dependent membrane reordering.
authors.affiliation: Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russia. Electronic address: kutuzovnp@gmail.com.
authors.forename: Nikolay P
authors.initials: NP
authors.lastname: Kutuzov
authors.affiliation: Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russia.
authors.forename: Alexey R
authors.initials: AR
authors.lastname: Brazhe
authors.affiliation: Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russia.
authors.forename: Georgy V
authors.initials: GV
authors.lastname: Maksimov
authors.affiliation: All-Russian Research Institute for Optical and Physical Measurements, Moscow, Russia.
authors.forename: Olga E
authors.initials: OE
authors.lastname: Dracheva
authors.affiliation: All-Russian Research Institute for Optical and Physical Measurements, Moscow, Russia.
authors.forename: Vladimir L
authors.initials: VL
authors.lastname: Lyaskovskiy
authors.affiliation: All-Russian Research Institute for Optical and Physical Measurements, Moscow, Russia.
authors.forename: Fedor V
authors.initials: FV
authors.lastname: Bulygin
authors.affiliation: Biophysics Department, Biological Faculty, Moscow State University, Moscow, Russia.
authors.forename: Andrey B
authors.initials: AB
authors.lastname: Rubin
mesh_terms: D000465:Algorithms; D000818:Animals; D016880:Anisotropy; D002338:Carotenoids / Q000378:metabolism*; D007834:Lasers; D008051:Lipid Bilayers / Q000378:metabolism; D018613:Microscopy, Confocal; D008954:Models, Biological; D009186:Myelin Sheath / Q000378:metabolism*; D011896:Rana temporaria; D012584:Sciatic Nerve / Q000378:metabolism*; D013059:Spectrum Analysis, Raman / Q000295:instrumentation / Q000379:methods*
chemical_list: D008051:Lipid Bilayers; D002338:Carotenoids