摘要:
Currently, the major measures of preventing and controlling microbial infection are vaccinations and drugs. However, the appearance of drug resistance microbial mounts is main obstacle in current anti-microbial therapy. One of the most ubiquitous actin-binding proteins, non-muscle myosin II (NM II) plays a crucial role in a wide range of cellular physiological activities in mammals, including cell adhesion, migration, and division. Nowadays, growing evidence indicates that aberrant expression or activity of NM II can be detected in many diseases caused by microbes, including viruses and bacteria. Furthermore, an important role for NM II in the infection of some microbes is verified. Importantly, modulating the expression of NM II with small hairpin RNA (shRNA) or the activity of it by inhibitors can affect microbial-triggered phenotypes. Therefore, NM II holds the promise to be a potential target for inhibiting the infection of microbes and even treating microbial-triggered discords. In spite of these, a comprehensive view on the functions of NM II in microbial infection and the regulators which have an impact on the roles of NM II in this context, is still lacking. In this review, we summarize our current knowledge on the roles of NM II in microbial-triggered discords and provide broad insights into its regulators. In addition, the existing challenge of investigating the multiple roles of NM II in microbial infection and developing NM II inhibitors for treating these microbial-triggered discords, are also discussed.
摘要:
To explore the involvement of protein lysine acetylation in the conversion of muscle to meat, a quantitative analysis of the acetylome in postmortem porcine muscle with or without antemortem stress was conducted. In total, 771 acetylpeptides containing 681 lysine acetylation sites mapping to 176 acetylproteins were identified. Acetylproteins were enriched in muscle contraction, carbohydrate metabolism, cell apoptosis and calcium signaling. Bioinformatic analysis suggests that preslaughter handling may be associated with glycolysis in postmortem muscle and the overall meat quality, via acetylation of multiple enzymes of glycogenolysis/glycolysis, regulate rigor mortis via acetylation of contractile, ATP production and calcium signaling-related proteins, and regulate stress response, cell apoptosis and meat tenderization via regulating the functions of heat shock proteins and permeability transition pore complex. This study provides the first overview of the acetylome in postmortem muscle as affected by preslaughter handling and broadens knowledge of the biochemistry regulating meat quality development.
摘要:
Nucleolin is a multifunctional phosphoprotein and is involved in protecting from myocardial ischemia/reperfusion (I/R) injury. The function of nucleolin is regulated by posttranslational modifications, including phosphorylation and glycosylation. To study whether phosphorylation of nucleolin (P-nucleolin) was involved in the protection from myocardial I/R injury. We investigated the expression pattern of P-nucleolin (Thr-76 and 84) in hearts subjected to I/R injury, or rat cardiac myoblast cells (H9C2) subjected to hydrogen peroxide (H 2 O 2 ). The results showed that the expression of P-nucleolin and the ratio of P-nucleolin/nucleolin were significantly increased both in vivo and in vitro. Mutant nucleolin was obtained by site directed mutagenesis in vitro: threonine at 76 and 84 was replaced by alanine, and we found that the protective effect of nucleolin on apoptosis induced by oxidative stress was dependent on its phosphorylation at 76 and 84 in H9C2 cells. Furthermore, the cardio-protective roles of P-nucleolin (Thr-76 and 84) in H9C2 cardiomyocytes, were attributable to the upregulation of microRNA (miR)-21. Further analysis found that P-nucleolin (Thr-76 and 84) could bind to miR-21, and P-nucleolin colocalized with argonaute 2 (Ago2) in cytoplasm and could interact with Ago2 in a RNA-independent manner under cell oxidative stress. The current study revealed that P-nucleolin (Thr-76 and 84) increased in I/R injury myocardium, P-nucleolin was indispensable to upregulate miR-21 and inhibited apoptosis induced by H 2 O 2 in H9C2 cardiomyocytes. These findings provided new insight into the molecular mechanisms of nucleolin in myocardial I/R injury and oxidative stress cells.
摘要:
An adulteration of high-price oil has been an important concern in agri-food fraud problems. Triacylglycerols are the main components of edible plant oils, which play an important role as target for adulteration detections. The objective is to evaluate the utility of triacylglycerol profiles in the detection of adulteration in high priced oils. An effective method is established to detect adulteration of high priced oils based on triacylglycerol profiles and chemometrics. Triacylglycerol profiles of edible oils are analyzed by an APCI-MS3-IT-MS. All triacylglycerol compounds are quantified by normalization of the chromatographic peak area in selected reaction monitoring (SRM) mode based on MS3 fragment ion pairs, which are used to eliminate interference from the isobaric species of triacylglycerol. The results of the hierarchical cluster analysis (HCA) and random forest (RF) classification algorithm indicated that peanut, soybean, sesame, sunflower seed, and linseed oils are completely classified into five groups based on their triacylglycerol profiles. Finally, a recursive support vector machine (R-SVM) discriminant model is established, which can successfully identify adulteration of high priced oil with cheaper edible oils at a concentration of as low as 4% with an accuracy of 93.7%. Practical Applications: The triacylglycerol profiles of edible plant oils are analyzed by RPLC-APCI-IT-MS. The SRM scan mode based on MS3 fragment ion pairs can eliminate interference of triacylglycerol isomers. The discriminant model for adulterated high-price oils is established by R-SVM. HCA, and RF can classify the five kinds of edible plant oil. The triacylglycerol of five edible plant oils is analyzed by RPLC-APCI-MS3-IT-MS. The triacylglycerol data matrix is submitted using unsupervised (HCA) and supervised (RF) chemometric methods to classify five kinds of edible plant oil. A discriminant model established with the R-SVM can be used to identify adulterated linseed oil samples (>= 4%) with an accuracy of 93.7%.
摘要:
The objective of this study was to investigate the effects of ubiquitin-proteasome pathway on meat tenderisation. The sheep muscle longissimus lumborum was injected with or without PYR-41 (inhibitor of ubiquitination) or MG-132 (inhibitor of proteasome). Muscle samples were collected at 6, 15, 24 and 48h after injection. Myofibrillar protein degradation, muscle ultrastructure and sarcomere length were determined. Results showed that inhibition of proteasome or ubiquitination affected sarcomere length at 48h after treatments. Destruction of muscle ultrastructure in both treatments was reduced when compared to control. Inhibition of proteasome produced different fragments of myofibrillar proteins in comparison with control at 48h. In conclusion, ubiquitin-proteasome plays a role in postmortem proteolysis and might contribute to meat tenderisation.
期刊:
现代食品科技,2015年31(2):196-204 and 231 ISSN:1673-9078
作者机构:
[刘焱; 周赞; 罗灿; 刘伦伦] College of Food Science and Technology, Hunan Agricultural University, Changsha, China;[刘焱] Hunan Province Key Laboratory of Food Science and Biotechnology, Changsha, China
作者机构:
[刘焱; 陈力力; 杨伊磊; 娄爱华] College of Food Science and Technology Hunan Agricultural University, Changsha, China;[刘焱; 陈力力; 青文哲; 娄爱华] Hunan Provincial Key Laboratory of Food Science and Biotechnology, Changsha, China
作者机构:
[刘泽宇] School of Aeronautics, Northwestern Polytechnical University, Xi'an, China;[朱旗] Horticulture and Landscape College, Hunan Agricultural University, Changsha, China;[刘焱] Hunan Province Key Laboratory of Food Science and Biotechnology, Hunan Agricultural University, Changsha, China;[刘焱; 罗灿] College of Food Science and Technology, Hunan Agricultural University, Changsha, China
通讯机构:
College of Food Science and Technology, Hunan Agricultural University, Changsha, China
摘要:
目的:研究茶多酚对氧化脂肪-蛋白质体系的作用机理。方法:利用分光光度计和红外光谱检测法对冻藏条件下氧化脂肪-蛋白质模拟体系中肌原纤维蛋白巯基含量、表面疏水性和二级结构进行研究。结果:在冻藏过程中,添加氧化6 h鱼油的肌原纤维蛋白液,巯基含量的减少和表面疏水性的增加最显著,其减少值和增加值分别为28.62 %和53.72 %;同时β-折叠、α-螺旋的减少和β-转角、无规卷曲的增加也最明显。添加0.05%茶多酚的三个组合与其相应的对照组相比,巯基含量的减少、表面疏水性的增加和二级结构的改变都较为缓慢,其中茶多酚抑制巯基含量减少的效果十分显著。结论:氧化鱼油能加速蛋白质的变性,且氧化程度越大,加速效果越明显;而茶多酚能够通过抑制巯基含量的减少来抑制鱼油氧化而导致的蛋白质变性。 Objective: To study the effects of tea polyphenols on the oxidation of fat -protein system. Methods: Sulfhydryl content,surface hydrophobicity and secondary structure of the myofibrillar protein of the oxidation fat-protein system in frozen storage conditions had been studied by spectrophotometer,fluorescence spectrophotometer and infrared spectrometer. Results: On frozen-storage conditions,in the myofibrillar protein liquid,which have added oxidated 6 h fish oil,the decrease of sulphur content and increase of the surface hydrophobicity are most significant,the reduction and increase value is 28.62% and 53.72%,respectively. The reduction of β-pleated sheet,α-helix and the increase of random coil,β-bend are also most obvious. Compared with its corresponding control group,added 0.05% tea polyphenols,the decrease of sulfhydryl content,increase of the surface hydrophobicity and the change of the secondary structure are more slowly. Especially,the effect of tea polyphenols inhibiting sulphur content is significant.Conclusion: Oxidized fish oil can accelerate protein denaturation,and the greater the degree of fish oil oxidation is,the more obvious the accelerations are. And tea polyphenols can inhibit sulfhydryl content reducing,and suppress the protein denaturation that is caused by fish oil oxidation.