Determining the rates of \alpha-tocopherol movement in DPPC vesicles using Small Angle Neutron Scattering

Published

January 17, 2025

Author(s)

Dominik Dziura, Isabelle Dib, Omotayo Gbadamosi, Stuart R. Castillo, Maksymilian Dziura, Elizabeth Kelley, Drew Marquardt

Abstract

-Tocopherol (toc, vitamin E) is an essential nutrient sufficiently acquired through a balanced diet. This fat-soluble vitamin is most known for its antioxidative properties, however, its fundamental mechanism of action in cellular membranes remains unknown. To this end, we use time-resolved small angle neutron scattering (TR-SANS) and a contrast matching scheme to determine intervesicular exchange (kex) and intrabilayer flip-flop (kf) rates in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles. Moreover, we investigate the role of sample concentration and various types of cyclodextrins in affecting these rates. For the 25 mg/mL sample concentration it was determined that kex and kf were 1.35 ± 0.03 x 10-3 min-1 and 0.54 ± 0.10 x 10-3 min-1, which represent half-lives (T1/2) of 513.4 ± 11.7 and 1285.1 ± 242.7 minutes, respectively. Differential scanning calorimetry confirmed the observed timescales of toc movement.

Citation

Biophysical Journal

Pub Type

Journals

Keywords

tocopherol, vitamin E, DPPC, lipid, exchange, flip-flop, small angle neutron scattering

Citation

Dziura, D. , Dib, I. , Gbadamosi, O. , Castillo, S. , Dziura, M. , Kelley, E. and Marquardt, D. (2025), Determining the rates of \alpha-tocopherol movement in DPPC vesicles using Small Angle Neutron Scattering, Biophysical Journal (Accessed January 31, 2025)