鸭血清胆碱酯酶的纯化及性质研究

首次采用新技术双水相萃取方法作为鸭血清胆碱酯酶(EC.3.1.1.8 CHE) 纯化的第一步,后经 DEAE-Sephadex A50,sephadex G200 柱层析,获得电泳纯鸭血清胆碱酯酶,提纯倍数1018倍,酶活力回收43.4%,比活274.9U/mg。鸭血清胆碱酯酶性质研究表明:此酶是糖蛋白和酸性蛋白水解酶,等电点 4.2 左右,最适 pH7.5 左右;对底物碘化硫代丁酰胆碱的 K_m=9.8×10^-5mol/L;SDS-PAGE 电泳和聚丙烯酰胺梯度电泳表明,鸭血清胆碱酯酶以相同亚基组成的不同聚合体形式存在,亚基分子量 78000,具有完整的酶活性.不同聚合体带电状态相同.     

亚油酸体系脂质过氧化引起的DNA损伤研究

用含两个双键的不饱和脂肪酸-亚油酸作为模型化合物,分析其过氧化程度,同时检测了由于脂质过氧化而引起的DNA损伤,结果表明:在脂质过氧化过程中,DNA与亚油酸过氧化产物反应生成一种荧光物质、其最大激发波长315nm最大发射波长410nm并随着氧化时间增加而增加,与此同时,双链DNA百分含量明显下降,DNA-溴乙锭复合物荧光显著降低,反映了DNA二级结构受到破坏.上述结果揭示了脂质过氧化产物在自由基引起DNA的损伤中可能起重要作用     

杂交试验中的最佳样本含量

杂交试验是一项费时费钱的工作,因此在进行试验之前如能进行严密的设计,给出试验所需的样本大小是十分必要的,统计学中常见的估计样本容理的公式不宜应用于杂交试验,本文分两种情况给出了杂交试验中样本容量的估计公式,据此估计出的样本容量安排杂交试验,可在满足试验者要求的条件下,使试验的总成本最低或使试畜的总头数最少。     

The Prevention Effect of Bacillus subtilis on Escherichia coli–Induced Mastitis in Mice by Suppressing the NF-κB and MAPK Signaling Pathways

Probiotics and Antimicrobial Proteins - Mastitis, common inflammation of the mammary gland, caused by various factors, is a challenge for the dairy industry. Escherichia coli (E. coli), a...     

Genome-wide identification,classification, and expression profiling of serine esterases and other esterase-related proteins in the tobacco hornworm,Manduca sexta

Serine esterases (SEs) are hydrolases that catalyze the conversion of carboxylic esters into acids and alcohols. Lipases and carboxylesterases constitute two major groups of SEs. Although over a hundred of insect genomes are known, systematic identification and classification of SEs are rarely performed, likely due to large size and complex composition of the gene family in each species. Considering their key roles in lipid metabolism and other physiological processes, we have categorized 144 M. sexta SEs and SE homologs (SEHs), 114 of which contain a motif of GXSXG. Multiple sequence alignment and phylogenetic tree analysis have revealed 39 neutral lipases (NLs), 3 neutral lipase homologs (NLHs), 11 acidic lipases (ALs), 3 acidic lipase homologs (ALHs), a lipase-3, a triglyceride lipase, a monoglyceride lipase, a hormone-sensitive lipase, and a GDSL lipase. Eighty-three carboxylesterase genes encode 29 α-esterases (AEs), 12 AEHs (e.g., SEH4-1–3), 20 feruloyl esterases (FEs), 2 FEHs, 2 β-esterases (BEs), 2 integument esterases (IEs), 1 IEH, 4 juvenile hormone esterases, 2 acetylcholinesterases, gliotactin, 6 neuroligins, neurotactin, and an uncharacteristic esterase homolog. In addition to these GXSXG proteins, we have identified 26 phospholipases and 13 thioesterases. Expression profiling of these genes in specific tissues and stages has provided insights into their functions including digestion, detoxification, hormone processing, neurotransmission, reproduction, and developmental regulation. In summary, we have established a framework of information on SEs and related proteins in M. sexta to stimulate their research in the model species and comparative investigations in agricultural pests or disease vectors.     

山西糜子核心种质分子身份证构建

为快速鉴定糜子(Panicum miliaceum)资源, 建立分子标记检测平台, 以272份山西糜子核心种质为研究材料, 利用85对简单重复序列(SSR)引物, 应用ID Analysis 4.0软件, 构建DNA分子身份证。结果表明, 对85对SSR引物进行筛选, 发现20对引物组合(RYW67、RYW53、RYW37、RYW65、RYW62、RYW77、RYW5、RYW49、RYW84、RYW19、RYW11、RYW40、RYW54、RYW28、RYW31、RYW7、RYW16、RYW8、RYW9和RYW18)可区分272份材料。共检测到等位变异(Na) 60个, 平均每个位点检出3个; Shannon多样性指数(I)为0.957 8 (RYW16)-1.096 7 (RYW5), 平均值为1.055 2; 多态性信息含量(PIC)为0.604 4 (RYW77)-0.753 0 (RYW37), 平均值为0.692 1。利用20对引物构建山西糜子核心种质的字符串、条形码和二维码DNA分子身份证, 可为种质身份标识和溯源提供实践路径。     

STUDY ON STROMATOLITIC DECLINE EVENT IN TERMINAL PRECAMBRIAN

In Precambrian, stromatolites, especially columnar stromatolites, underwent a marked evolutionary process from beginning of development through extensive flourish to rapid decline. The present paper makes a discussion on the exact data and cause of the stromatolitic decline in an attempt to reveal the evolution of biosphere and change of ecological environments in the terminal Precambrian according to a study of the stromatolitic decline event.     

EVALUATION OF EXTRACTS FROM BAMBOO FOR BIOLOGICAL ACTIVITY AGAINST CULEX PIPIENS PALLENS

Abstract The extracts from 7 species of bamboo were tested for larvicidal activity against Culex pipiens pallens . At the tested concentration, the extracts of selected bamboo had different degree of toxic effects on the fourth instar larvae of Culex pipiens pallens . Among them, the extracts of Pleioblastus juxianensis, Brachystachyum albostriatum, Phyllostachys platyglossa and Pleioblastus amarus were found to be effective with LC₅₀values at 24 h of 30.65 mg/L, 53.94 mg/L, 41.21 mg/L and 54.49 mg/L respectively, against Culex pipiens pallens larvae. The extract of Pleioblastus juxianensis by Soxhlet method showed stronger activity than the extract obtained by interval-shaking, the LC₅₀ of which were 30.65 mg/L and 48.34 mg/L, respectively. The diethyl ether extract of Pleioblastus juxianensis exhibited better larvicidal activity than the methanol extract and the petroleum ether extract. The results would help to provide the basis for the study of environment acceptable pesticide for mosquito control, and also help to comprehensively utilize the source of bamboo.