亚油酸诱导植物乳杆菌p-8产生共轭亚油酸的蛋白组和类组蛋白乙酰化分析

Proteome and Histone-Like Acetylation Analysis of Conjugated Linoleic Acid Production by Lactobacillus plantarum p-8 Induced by Linoleic Acid

研究亚油酸(linoleic acid,LA)诱导下植物乳杆菌(Lactobacillus plantarum)p-8的蛋白组和类组蛋白乙酰化水平差异,探究共轭亚油酸(conjugated linoleic acid,CLA)产生的机制。结果表明,LA的最佳诱导质量浓度为1 mg/mL,在此质量浓度条件下,蛋白质组学分析发现,烯酰-酰基载体蛋白还原酶、酰基载体蛋白等脂肪酸合成的关键蛋白因子下调,脂肪酸合成下调,乙酰基转移酶水平上调。Western blot结合体外添加NaAc实验表明,乙酰辅酶A含量增加导致类组蛋白乙酰化水平提升。实时聚合酶链式反应检测显示,添加LA和NaAc使CLA相关酶、转录调控因子和Sigma因子的mRNA表达升高,CLA含量也提高。相关性分析得出,乙酰辅酶A与LA水合酶转录水平和CLA含量之间呈显著正相关,揭示乙酰辅酶A和乙酰基转移酶含量上调导致类组蛋白乙酰化加强而上调CLA合成。结果为分子改良或科学调控乳酸菌以提高CLA转化率奠定了基础。

In this study,changes in proteome and histone-like acetylation levels of Lactobacillus plantarum p-8 induced by linoleic acid(LA)were explored to investigate the mechanism of conjugated linoleic acid(CLA)production.The results showed that the optimal concentration of LA for inducing CLA production was 1 mg/mL.Proteomic analysis revealed that at this concentration,key protein factors for fatty acid synthesis such as enoyl acyl carrier protein(ACP)reductase and acyl carrier proteins were down-regulated,fatty acid synthesis was down-regulated,and acetyltransferase was up-regulated.Western blot showed that the increase in the content of acetyl-CoA upon NaAc addition resulted in elevated histone-like protein acetylation levels.The addition of LA and NaAc increased the mRNA expression of CLA-related enzymes,transcription factors(TF)and Sigma factors,as determined by real-time polymerase chain reaction(real-time PCR),and increased the transformation rate of CLA.Correlation analysis yielded a significant positive correlation between the transcriptional levels of acetyl-CoA and linoleic acid hydratase(CLA-hy)and the transformation rate of CLA,revealing that the up-regulation of acetyl-CoA and acetyltransferase contents led to enhanced histone-like acetylation and consequent up-regulation of CLA synthesis.These results provide a basis for molecular modification and scientific regulation of lactic acid bacteria to improve CLA conversion.