TY - JOUR
T1 - Palmitate interaction with physiological states of myoglobin
AU - Shih, Lifan
AU - Chung, Youngran
AU - Sriram, Renuka
AU - Jue, Thomas
PY - 2014
Y1 - 2014
N2 - 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.
AB - 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.
KW - Bioenergetics
KW - Fatty acid
KW - Lipid
KW - Metabolism
KW - NMR
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U2 - 10.1016/j.bbagen.2013.10.028
DO - 10.1016/j.bbagen.2013.10.028
M3 - Article
C2 - 24482816
AN - SCOPUS:84887264757
VL - 1840
SP - 656
EP - 666
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
SN - 0304-4165
IS - 1
ER -