Open Access

Spectroscopic studies of D-α-tocopherol concentration-induced transformation in egg phosphatidylcholne vesicles

  • Krzysztof Dwiecki1,
  • Paweł Górnas1,
  • Agnieszka Wilk3,
  • Małgorzata Nogala-Kałucka2, 4 and
  • Krzysztof Polewski1Email author
Cellular & Molecular Biology LettersAn International Journal200612:59

https://doi.org/10.2478/s11658-006-0059-6

Received: 18 April 2006

Accepted: 9 August 2006

Published: 24 November 2006

Abstract

The effects of embedding up to 60 mol% of α-tocopherol (α-Toc) on the morphology and structure of the egg phosphatidylcholine (PC) membrane were studied using spectroscopic techniques. The resulting vesicles were subjected to turbidometric and dynamic light scattering measurements to evaluate their size distribution. The α-Toc intrinsic fluorescence and its quenching was used to estimate the tocopherol position in the membrane. Optical microscopy was used to visualize morphological changes in the vesicles during the inclusion of tocopherol into the 2 mg/ml PC membrane. The incorporation of up to 15 mol% of tocopherol molecules into PC vesicles is accompanied by a linear increase in the fluorescence intensity and the simultaneous formation of larger, multilamellar vesicles. Increasing the tocopherol concentration above 20 mol% induced structural and morphological changes leading to the disappearance of micrometer-sized vesicles and the formation of small unilamellar vesicles of size ranging from 30 to 120 nm, mixed micelles and non-lamellar structures.

Key words

Egg phosphatidylcholine Tocopherol Fluorescence Vesicles Optical microscopy Dynamic light scattering

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