The First Department of Medicine, Wakayama Medical University, 811-1 Kimi-idera, Wakayama 641-8509, Japan.
Eur J Endocrinol. 2012 Feb;166(2):235-40. doi: 10.1530/EJE-11-0785. Epub 2011 Nov 2.
Ghrelin requires a fatty acid modification for binding to the GH secretagogue receptor. Acylation of the Ser3 residue of ghrelin is essential for its biological activities. We hypothesized that acyl-CoA is the fatty acid substrate for ghrelin acylation. Because serum octanoyl-CoA levels are altered by fatty acid oxidation disorders, we examined circulating ghrelin levels in affected patients.
Blood levels of acyl (A) and des-acyl (D) forms of ghrelin and acylcarnitine of patients with medium-chain acyl-CoA dehydrogenase (MCAD) deficiency and glutaric aciduria type II (GA2) were measured.
Plasma acyl ghrelin levels and A/D ratios increased in patients with MCAD deficiency or GA2 when compared with normal subjects. Reverse-phase HPLC confirmed that n-octanoylated ghrelin levels were elevated in these patients.
Changing serum medium-chain acylcarnitine levels may affect circulating acyl ghrelin levels, suggesting that acyl-CoA is the substrate for ghrelin acylation.
胃饥饿素与 GH 促分泌素受体结合需要脂肪酸修饰。胃饥饿素 Ser3 残基的酰化对于其生物活性至关重要。我们假设酰基辅酶 A 是胃饥饿素酰化的脂肪酸底物。由于血清辛酰基辅酶 A 水平可被脂肪酸氧化紊乱改变，我们检测了受影响患者的循环胃饥饿素水平。
测量了中链酰基辅酶 A 脱氢酶 (MCAD) 缺乏症和戊二酸血症 II 型 (GA2) 患者的酰基 (A) 和去酰基 (D) 形式胃饥饿素和酰基肉碱的血液水平。
与正常受试者相比，MCAD 缺乏症或 GA2 患者的血浆酰基胃饥饿素水平和 A/D 比值升高。反相高效液相色谱法证实这些患者的 n-辛酰化胃饥饿素水平升高。
血清中链酰基辅酶 A 水平的变化可能会影响循环酰基胃饥饿素水平，提示酰基辅酶 A 是胃饥饿素酰化的底物。
