Treleaven WD, Parmar YI, Gorrissen H, Cushley RJ. Orientational order of cholesteryl oleate in low-density lipoprotein observed by 2H-NMR.
BIOCHIMICA ET BIOPHYSICA ACTA 1986;
877:198-210. [PMID:
3718998 DOI:
10.1016/0005-2760(86)90135-9]
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Abstract
Cholesteryl oleate, selectively deuterated at various positions along the acyl chain, has been incorporated into fresh human serum low-density lipoprotein (LDL2). Temperature-dependent 2H-NMR spectra were recorded between 15 and 45 degrees C. For deuterons at C-2' and C-5' of the acyl chain, two 2H-NMR spectral components, a broad and a narrow signal, are observed. This is interpreted as reflecting the coexistence of two cholesteryl ester regions in the LDL2 core which possess different degrees of order. The C-2H bond order parameters, SCD, are approx. 0.12-0.20 for the more ordered region and approx. 0.04-0.06 for the less ordered region. Longitudinal relaxation times, T1, of deuterated cholesteryl oleate are found to increase between C-8' and the terminal -C2H3 group, which is consistent with an increased rate of chain motion toward the free ends of the ester acyl chains.
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