Jue Thomas, Shih Lifan, Chung Youngran
Department of Biochemistry and Molecular Medicine, University of California Davis, Davis, CA, 95616-8635, USA.
Lipids. 2017 Aug;52(8):711-727. doi: 10.1007/s11745-017-4272-z. Epub 2017 Jun 21.
Previous studies have shown that palmitic acid (PAM) and oleic acid (OLE) can bind myoglobin (Mb). How fatty acids (FA) with different carbon chain lengths and sulfate substitution interact with Mb remains uncertain. Indeed, C8:0 and C10:0 fatty acids do not perturb the intensities of the H-NMR MbCN signal intensity at FA:Mb ratios below 2:1. Starting with C12:0, C12:0-C16:0, FA induce a noticeable spectral change. C12:0 and C14:0 FA affect both the 5- and 8-heme methyl signals, whereas the C16:0 FA perturbs only the 8-heme methyl signal. All C12:0-C16:0 saturated FA induce upfield shifts in the -CH peak of different FA in the presence of Mb. Increasing the apparent solubility with a sulfate group substitution enhances the FA interaction of lauric sulfate (LAU 1-SO) but not palmitate sulfate acid (PAM 1-SO). The detergent (DET) property of FA has no significant contribution. Common positive, neutral, and negative DET at DET:Mb ratio of 1:1 induce no perturbation of the MbCN spectra. The experiment observations establish a basis to investigate the molecular mechanism underlying the FA interaction with Mb.
先前的研究表明，棕榈酸（PAM）和油酸（OLE）可以与肌红蛋白（Mb）结合。不同碳链长度和硫酸根取代的脂肪酸（FA）如何与Mb相互作用仍不确定。事实上，在FA:Mb比例低于2:1时，C8:0和C10:0脂肪酸不会干扰H-NMR MbCN信号强度。从C12:0开始，C12:0 - C16:0脂肪酸会引起明显的光谱变化。C12:0和C14:0脂肪酸会影响5-和8-血红素甲基信号，而C16:0脂肪酸仅干扰8-血红素甲基信号。在存在Mb的情况下，所有C12:0 - C16:0饱和脂肪酸都会使不同脂肪酸的-CH峰发生向上位移。用硫酸根取代增加表观溶解度会增强月桂基硫酸盐（LAU 1-SO）与FA的相互作用，但不会增强棕榈酸硫酸盐（PAM 1-SO）的相互作用。FA的去污剂（DET）性质没有显著贡献。在DET:Mb比例为1:1时，常见的正、中性和负DET不会引起MbCN光谱的扰动。这些实验观察结果为研究FA与Mb相互作用的分子机制奠定了基础。
