枯草芽孢杆菌抗茵肽生物合成的研究进展

革兰氏阳性菌模式生物----枯草芽孢杆菌能分泌多种肽类及由肽类衍生的抗菌活性物质,按合成途径不同,可分为核糖体肽和非核糖体肽.其中,非核糖体肽分子量较小,一般为 3000Da以下,其生物合成是通过多功能复合酶系----非核糖体肽链合成酶来完成的,多发生在菌体生长停止之后; 而核糖体肽分子量较大,其合成多于菌体快速生长时期.非核糖体肽链合成酶和核糖体肽的合成及其调控均需基因参与,而这一系列基因就构成了各种抗茵肽生物合成的基因簇.对核糖体肽和非核糖体肽的生物合成及其相关调控机制进行了综

枯草芽孢杆菌抗茵肽生物合成的研究进展

革兰氏阳性菌模式生物----枯草芽孢杆菌能分泌多种肽类及由肽类衍生的抗菌活性物质,按合成途径不同,可分为核糖体肽和非核糖体肽.其中,非核糖体肽分子量较小,一般为 3000Da以下,其生物合成是通过多功能复合酶系----非核糖体肽链合成酶来完成的,多发生在菌体生长停止之后; 而核糖体肽分子量较大,其合成多于菌体快速生长时期.非核糖体肽链合成酶和核糖体肽的合成及其调控均需基因参与,而这一系列基因就构成了各种抗茵肽生物合成的基因簇.对核糖体肽和非核糖体肽的生物合成及其相关调控机制进行了综

大肠杆菌细胞抽提物制备方案的简化与优化

无细胞蛋白表达系统是一种将目的蛋白在体外进行表达的新技术和新方法,已广泛应用到蛋白质组学、蛋白质结构和功能等领域的研究中。在无细胞蛋白表达系统中,细胞抽提物的制备是关键因素之一。通过对大肠杆菌细胞抽提物制备过程中离心速度、预孵化和透析等参数的考察,利用绿色荧光蛋白作为报告蛋白,可以得到一个细胞抽提物制备的简化方案。采用相对低的转速(12 000×g,10 min),简易空孵化即可制备出活性高的细胞抽提物,用于无细胞体系蛋白表达,其表达的绿色荧光蛋白产量为209μg/mL。与传统的大肠杆菌细胞抽提物S30相比较,新方案将使时间与成本节省62%,产量是传统方法的2.6倍,使无细胞蛋白表达技术的操作快速、高通量的优势更加明显

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel

JUNO sensitivity on proton decay p → ν K + searches*

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the $p\to \bar{\nu} K^+$ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar{\nu} K^+$ is 36.9% ± 4.9% with a background level of $0.2\pm 0.05({\rm syst})\pm$$0.2({\rm stat})$ events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is $9.6 \times 10^{33}$ years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies