蛋白质乙酰化修饰及AMPK对宰后肌肉糖酵解的调控作用

发布时间：2018-05-29 18:28

本文选题：PSE肉 + 糖酵解　；参考：《西北农林科技大学》2015年硕士论文

【摘要】：PSE肉表面苍白、质地松软没弹性、并且肌肉表面渗出肉汁,由于其品质、肉色较差,给肉品行业带来了巨大的经济损失。宰前应激会加速糖酵解的进行,导致乳酸积累,从而产生PSE肉,但是关于宰后肌肉糖酵解调控的分子机制还是未知的。蛋白质赖氨酸乙酰化是一个重要的转录后修饰方式,在调控细胞各种活动方面发挥着关键的作用。非组蛋白的乙酰化已经被发现,大量的证据表明其在调控能量代谢方面起着非常重要的作用。本文利用小鼠宰前游泳模拟宰前应激,腹腔注射5-氨基咪唑-4-甲酰胺核苷酸转甲酰酶(AICAR)激活AMPK,腹腔注射去乙酰酶抑制剂和乙酰转移酶抑制剂改变乙酰化水平。通过检测宰后0 h、45 min和24 h的pH值、乳酸含量和糖酵解酶活性来反映宰后肌肉糖酵解;通过免疫印迹检测乙酰化水平,确定AMPK及蛋白质乙酰化对宰后肌肉的影响。获得的主要研究结果如下:1.宰前应激通过提高宰后肌肉的乙酰化水平促进糖酵解。利用小鼠宰前游泳模拟宰前应激,检测宰后0 h、45 min和24 h的pH值、乳酸含量和糖酵解酶活性发现宰前游泳加速了宰后肌肉的糖酵解。通过免疫印迹检测乙酰化水平发现,宰前游泳提高了宰后肌肉的乙酰化水平。结果表明,宰前游泳可以通过提高宰后肌肉的乙酰化水平来促进宰后肌肉的糖酵解。2.提高蛋白质的乙酰化水平促进糖酵解。利用小鼠宰前腹腔注射去乙酰酶抑制剂和乙酰转移酶抑制剂,检测宰后0 h、45 min和24 h的pH值、乳酸含量和糖酵解酶活性发现,腹腔注射去乙酰酶抑制剂加速了宰后肌肉糖酵解的进行;反之,腹腔注射乙酰转移酶抑制剂抑制了宰后肌肉糖酵解的进行。通过免疫印迹检测乙酰化水平发现,腹腔注射去乙酰酶抑制剂和乙酰转移酶抑制剂分别提高和降低了宰后肌肉的乙酰化水平。结果表明,提高蛋白质的乙酰化水平可以促进宰后肌肉的糖酵解。3.AMPK提高了宰后肌肉的乙酰化水平。利用小鼠宰前腹腔注射AMPK激活剂AICAR,免疫印迹检测发现,注射AICAR后,AMPK被激活。检测宰后0 h、45 min和24 h的pH值、乳酸含量和糖酵解酶活性发现,腹腔注射AICAR加速了宰后肌肉糖酵解的进行。免疫印迹检测发现,注射AICAR后提高了宰后肌肉的乙酰化水平。AMPK可以通过提高宰后肌肉的乙酰化水平来促进宰后肌肉的糖酵解。
[Abstract]:PSE meat surface is pale, soft and inelastic, and muscle surface oozes out gravy, because of its quality, meat color is poor, has brought huge economic loss to meat industry. Pre-mortem stress accelerates glycolysis and leads to the accumulation of lactic acid resulting in the production of PSE meat. However the molecular mechanism of postmortem muscle glycolytic regulation is still unknown. Lysine acetylation is an important post-transcriptional modification and plays a key role in regulating cell activities. Acetylation of nonhistone has been found, and there is a lot of evidence that it plays a very important role in regulating energy metabolism. AMPK was activated by intraperitoneal injection of 5-aminoimidazole-4-formamide nucleotide transformase (AICARA), and acetylation level was changed by intraperitoneal injection of deacetylase inhibitor and acetyltransferase inhibitor. The pH value, lactate content and glycolytic enzyme activity of postmortem muscle were measured at 45 min and 24 h after slaughter, and the effects of AMPK and protein acetylation on postmortem muscle were determined by Western blotting. The main results obtained are as follows: 1. Pre-mortem stress promotes glycolysis by increasing the acetylation level of postmortem muscles. Pre-mortem swimming was used to simulate premortem stress in mice. The pH value, lactate content and glycolytic enzyme activity of postmortem muscle were measured for 45 min and 24 h after slaughter. It was found that pre-mortem swimming accelerated the glycolysis of postmortem muscle. The level of acetylation in postmortem muscles was increased by Western blotting analysis, and it was found that pre-mortem swimming improved the acetylation level of postmortem muscles. The results showed that pre-mortem swimming could promote glycolysis of postmortem muscles by improving the acetylation level of postmortem muscles. Increase the level of acetylation of protein to promote glycolysis. Deacetylase inhibitor and acetyltransferase inhibitor were injected intraperitoneally into mice before slaughter. The pH value, lactate content and glycolytic enzyme activity were detected at 45 min and 24 h after slaughter. Intraperitoneal injection of deacetylase inhibitor accelerated postmortem muscle glycolysis, whereas intraperitoneal injection of acetyltransferase inhibitor inhibited postmortem muscle glycolysis. The level of acetylation was detected by Western blotting. It was found that intraperitoneal injection of deacetylase inhibitor and acetyltransferase inhibitor increased and decreased the acetylation level of postmortem muscle, respectively. The results showed that increasing the level of protein acetylation could promote glycolysis of postmortem muscle. 3. AMPK increased the level of acetylation of postmortem muscle. AMPK activator was injected intraperitoneally into mice before slaughter. Western blot analysis showed that AMPK was activated after AICAR injection. The pH value, lactate content and glycolytic enzyme activity at 45 min and 24 h after slaughter were detected. The results showed that intraperitoneal injection of AICAR accelerated the glycolysis of postmortem muscle. Western blot analysis showed that after AICAR injection, the acetylation level of postmortem muscle was increased. AMPK could promote glycolysis of postmortem muscle by improving the acetylation level of postmortem muscle.
【学位授予单位】：西北农林科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S852.2

【相似文献】