酰基辅酶 A 衍生物对人脂氧合酶同工酶的抑制作用研究。
Inhibitory Investigations of Acyl-CoA Derivatives against Human Lipoxygenase Isozymes.
机构信息
Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, CA 95064, USA.
Department of Biochemistry and Pharmacology, University of Melbourne, Melbourne, VIC 3010, Australia.
出版信息
Int J Mol Sci. 2023 Jun 30;24(13):10941. doi: 10.3390/ijms241310941.
Lipid metabolism is a complex process crucial for energy production resulting in high levels of acyl-coenzyme A (acyl-CoA) molecules in the cell. Acyl-CoAs have also been implicated in inflammation, which could be possibly linked to lipoxygenase (LOX) biochemistry by the observation that an acyl-CoA was bound to human platelet 12-lipoxygenase via cryo-EM. Given that LOX isozymes play a pivotal role in inflammation, a more thorough investigation of the inhibitory effects of acyl-CoAs on lipoxygenase isozymes was judged to be warranted. Subsequently, it was determined that C18 acyl-CoA derivatives were the most potent against h12-LOX, human reticulocyte 15-LOX-1 (h15-LOX-1), and human endothelial 15-LOX-2 (h15-LOX-2), while C16 acyl-CoAs were more potent against human 5-LOX. Specifically, oleoyl-CoA (18:1) was most potent against h12-LOX (IC = 32 μM) and h15-LOX-2 (IC = 0.62 μM), stearoyl-CoA against h15-LOX-1 (IC = 4.2 μM), and palmitoleoyl-CoA against h5-LOX (IC = 2.0 μM). The inhibition of h15-LOX-2 by oleoyl-CoA was further determined to be allosteric inhibition with a of 82 +/- 70 nM, an α of 3.2 +/- 1, a β of 0.30 +/- 0.07, and a β/α = 0.09. Interestingly, linoleoyl-CoA (18:2) was a weak inhibitor against h5-LOX, h12-LOX, and h15-LOX-1 but a rapid substrate for h15-LOX-1, with comparable kinetic rates to free linoleic acid ( = 7.5 +/- 0.4 s, = 0.62 +/- 0.1 µMs). Additionally, it was determined that methylated fatty acids were not substrates but rather weak inhibitors. These findings imply a greater role for acyl-CoAs in the regulation of LOX activity in the cell, either through inhibition of novel oxylipin species or as a novel source of oxylipin-CoAs.
脂质代谢是一个复杂的过程,对于产生能量至关重要,导致细胞内酰基辅酶 A(acyl-CoA)分子水平升高。酰基辅酶 A 也与炎症有关,这可能与脂氧合酶(LOX)的生物化学有关,因为观察到酰基辅酶 A 通过冷冻电镜与人类血小板 12-脂氧合酶结合。鉴于 LOX 同工酶在炎症中起着关键作用,因此有必要更彻底地研究酰基辅酶 A 对脂氧合酶同工酶的抑制作用。随后,确定 C18 酰基辅酶 A 衍生物对 h12-LOX、人网织红细胞 15-LOX-1(h15-LOX-1)和人内皮 15-LOX-2(h15-LOX-2)的抑制作用最强,而 C16 酰基辅酶 A 对人 5-LOX 的抑制作用更强。具体而言,油酰辅酶 A(18:1)对 h12-LOX(IC = 32 μM)和 h15-LOX-2(IC = 0.62 μM)的抑制作用最强,硬脂酰辅酶 A 对 h15-LOX-1(IC = 4.2 μM)的抑制作用最强,棕榈油酸酰辅酶 A 对 h5-LOX(IC = 2.0 μM)的抑制作用最强。进一步确定,油酰辅酶 A 对 h15-LOX-2 的抑制作用是别构抑制,Ki 值为 82 ± 70 nM,α 值为 3.2 ± 1,β 值为 0.30 ± 0.07,β/α 值为 0.09。有趣的是,亚油酸酰辅酶 A(18:2)对 h5-LOX、h12-LOX 和 h15-LOX-1 的抑制作用较弱,但对 h15-LOX-1 的快速底物,与游离亚油酸( = 7.5 ± 0.4 s, = 0.62 ± 0.1 µMs)具有可比的动力学速率。此外,还确定甲基化脂肪酸不是底物,而是较弱的抑制剂。这些发现表明酰基辅酶 A 在细胞中 LOX 活性的调节中可能发挥更大的作用,要么通过抑制新型氧化脂素,要么作为氧化脂素-CoA 的新来源。