Palmitate interaction with physiological states of myoglobin

Lifan Shih, Youngran Chung, Renuka Sriram, Thomas Jue

Research output: Contribution to journalArticle

18 Scopus citations

Abstract

Background: Previous studies have shown that palmitate (PA) can bind specifically and non-specifically to Fe(III) MbCN. The present study has observed PA interaction with physiological states of Fe(II) Mb, and the observations support the hypothesis that Mb may have a potential role in facilitating intracellular fatty acid transport. Methods: 1H NMR spectra measurements of the Mb signal during PA titration show signal changes consistent with specific and non-specific binding. Results: Palmitate (PA) interacts differently with physiological states of Mb. Deoxy Mb does not interact specifically or non-specifically with PA, while the carbonmonoxy myoglobin (MbCO) interaction with PA decreases the intensity of selective signals and produces a 0.15 ppm upfield shift of the PA methylene peak. The selective signal change upon PA titration provides a basis to determine an apparent PA binding constant, which serves to create a model comparing the competitive PA binding and facilitated fatty acid transport of Mb and fatty acid binding protein (FABP). Conclusions: Given contrasting PA interaction of ligated vs. unligated Mb, the cellular fatty acid binding protein (FABP) and Mb concentration in the cell, the reported cellular diffusion coefficients, the PA dissociation constants from ligated Mb and FABP, a fatty acid flux model suggests that Mb can compete with FABP transporting cellular fatty acid. General significance: Under oxygenated conditions and continuous energy demand, Mb dependent fatty acid transport could influence the cell's preference for carbohydrate or fatty acid as a fuel source and regulate fatty acid metabolism.

Original languageEnglish (US)
Pages (from-to)656-666
Number of pages11
JournalBiochimica et Biophysica Acta - General Subjects
Volume1840
Issue number1
DOIs
StatePublished - 2014

Keywords

  • Bioenergetics
  • Fatty acid
  • Lipid
  • Metabolism
  • NMR

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

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