Determining the rates of α-tocopherol movement in DPPC vesicles using small-angle neutron scattering

Published

February 1, 2025

Author(s)

Dominik Dziura, Isabelle Dib, Omotayo Gbadamosi, Stuart R. Castillo, Maksymilian Dziura, Ryan Murphy, 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

Volume

124

Issue

4

Pub Type

Journals

Download Paper

https://doi.org/10.1016/j.bpj.2025.01.008

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Keywords

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

Citation

Dziura, D. , Dib, I. , Gbadamosi, O. , Castillo, S. , Dziura, M. , Murphy, R. , Kelley, E. and Marquardt, D. (2025), Determining the rates of α-tocopherol movement in DPPC vesicles using small-angle neutron scattering, Biophysical Journal, [online], https://doi.org/10.1016/j.bpj.2025.01.008, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958612 (Accessed October 9, 2025)