组氨酸磷酸化修饰的鉴定方法及应用

蛋白质磷酸化是广受关注的翻译后修饰类型之一,组氨酸磷酸化作为一种非常见的磷酸化修饰,最早被发现在细菌和低等真核生物信号传导的级联反应中起关键作用.近年来研究显示,其在肿瘤发生发展过程中也可能扮演了重要角色.由于磷酸化组氨酸的化学不稳定性、低丰度、亚化学计量性质、缺乏特异性的富集试剂,导致研究手段缺乏,限制了人们对磷酸化...     

白细胞介素-6在酒精性肝病中的作用

酒精性肝病(alcoholic liver disease,ALD)是由于长期过量饮酒导致肝的内部组织发生炎症损伤的慢性肝病.乙醇及其衍生物在代谢过程中直接或间接诱导引起的肝炎症反应可能是ALD发病的重要机制.然而,该过程内在的细胞分子机制尚不明确.最新研究发现,白细胞介素-6(interleukin-6,IL-6)对...     

Expression and characteristics of the gene encoding azoreductase from Rhodobacter sphaeroides AS1.1737

A gene that encodes a protein with azoreductase activity was obtained by PCR amplification from Rhodobacter sphaeroides AS1.1737. The enzyme, with a molecular weight of 18.7 kD, was heterologously expressed in Escherichia coli and its azoreductase activity was characterized. Furthermore, the reduction mechanism of azo dyes catalyzed by the azoreductase was studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.     

Nongenomic testosterone calcium signaling. Genotropic actions in androgen receptor-free macrophages

Steroid hormones exert genotropic actions through members of the nuclear receptor family. Here, we have demonstrated genotropic actions of testosterone that are independent of intracellular androgen receptors (iAR). Through plasma membrane androgen receptors (mAR), testosterone induces a rapid rise in the intracellular free Ca(2+) concentration of iAR-free murine RAW 264.7 macrophages. This nongenomic testosterone signaling, which is independent of both iAR and estrogen receptors, does not in itself activate either the mitogen-activated protein kinase (MAPK) families ERK1/2, p38, and JNK/SAPK, the stably and transiently transfected c-fos promoter, or NO production. In the context of lipopolysaccharide (LPS) signaling, however, testosterone attenuates LPS activation of the c-fos promoter and NO production, which is abolished by the intracellular Ca(2+) chelator BAPTA. Testosterone also attenuates the LPS activation of p38 but not that of ERK1/2 and JNK/SAPK, and this attenuation is abrogated by BAPTA. Moreover, the p38 inhibitor, SB 203580, largely reduces LPS activation of the c-fos promoter and NO production, and the remaining levels are no longer regulated by testosterone. This study is the first to provide information on genotropic actions of mAR-mediated nongenomic testosterone Ca(2+) signaling by cross-talk with the LPS signaling pathway through p38 MAPK with impact on cell function.     

鲫耳石重量与年龄的关系及其在年龄鉴定中的作用

耳石重量在年龄组间重叠较少,大小相近的个体,年龄大的,即生长慢的耳石重量比年龄小的,即生长快的大,不同龄组之间耳石重量有显著差异（P＜0．05）,按年龄组在耳石重量与相应的体长作图,可初步判断观测年龄的可靠性,分析耳石重量频率分布能分离出体长相近,年龄不同的个体,其结构与耳石年轮观测的基本一致,耳石重量与年龄呈显著线性正相关（P＜0．05）,用耳石重量与年龄关系估算的年龄从耳石上直接读取的年龄无显著差异（P＞0．05）,文中对耳石重量直接用于确定鱼类年龄的可能性作了分析和探讨。     

体重和摄食水平对鳜和乌鳢身体的生化组成和能值的影响

本实验结果表明,野生鳜和乌鳢的干物质含量、蛋白质含量、脂肪含量和能值均随体重的增加而显著增加（Ｐ＜０．０５）,野生鳜灰分含量变随体重的增加而显著增加（Ｐ＜０．０５）,但野生乌鳢灰分含量与体重关系的回归方程则不显著（Ｐ＜０．０５）;实验鳜和乌鳢干物质含量、脂肪含量和能值均随摄食水平的增加而显著增加（Ｐ＜０．０５）,实验鳜蛋白含量和灰分含量与摄食水平关系的回归方程不显著（Ｐ＜０．０５）,实验乌鳢蛋白质     

有机相酶促酯化反应中水分调控技术的研究

在有机相酶促反应中,水含量是影响酶活力的关键因素.对异辛烷/正辛醇体系中柱状假丝酵母脂肪酶催化萘普森酯化反应中的水分调控技术进行了研究. 结果表明：水合盐对——Na₂SO₄·10H₂O/Na₂SO₄对系统水分的变化具有有效的缓冲作用;非极性硅藻土吸附固定酶,使之对水分的敏感性得到缓解;另外,加入分子筛去除副产物——“水”可促进酯化过程的进行.     

棉铃虫和玉米螟成虫复眼光反应特性的比较研究

通过记录棉铃虫和玉米螟复眼的网膜电图（Ｅｌｅｃｔｒｏｒｅｔｉｎｏｇｒａｍ,ＥＲＧ）比较了二者对光刺激的反应特性。结果如下：（１）二者具有相似的光谱反应曲线,均对５６２ｎｍ的光最敏感,另外对４００ｎｍ、４８３ｎｍ光也较敏感;（２）二者对这三种敏感光的光强度曲线近似,在一定范围内均近似线性递增,但玉米螟复眼ＥＲＧ在５６２ｎｍ和４８３ｎｍ下具有更高的反应幅度;（３）二者对白光的光强度曲线也近似,但随复眼适应状态及测试时间的不同,表现出不同的光敏感性。在相同条件下,棉铃虫复眼表现出更强的敏感性;同种昆虫复眼夜间比白天敏感,暗眼比亮眼敏感;（４）对不同测试时间复眼明暗状态转化的比较表明,棉铃虫复眼的ＥＲＧ反应具有更强的昼夜节律性。     

黄鳝二价体上微量DNaseⅠ敏感性和限制性内切酶原位切割分析

采用DNase Ⅰ超敏感性分析和限制性内切酶介导的原位切口平移技术(Restriction Enzyme Nick Translation,RE-NT)对黄鳝二价体基因组结构进行了分析研究。已知DNaseⅠ超敏感性与潜在活性基因分布密切相关。结果表明,经DNaseⅠ介导的原位切口平移处理,在黄鳍二价体上可展现类D带带型,而由限制性内切酶介导的原位切口平移结果显示,AluⅠ和MspⅠ均在黄鳝二价体上诱导产生类G带带型,HpaⅡ和HaeⅢ则优先切割5号二价体上一特定区域,诱导出一段由标记信号所构成的类C带,对上述结果进行了分析和讨论。     

人多肽链延伸因子1α四个反转录假基因的鉴别与定位

人多肽链延伸因子1α基因EEF1A是一个在蛋白质合成过程中起重要作用的看家基因。通过对已有GenBank、GDB等数据库的综合分析,鉴别了4个人类多肽链延伸因子1α基因的反转录假基因,并分别将其精细定位于4q2 5、7p15-21、9q34和19q13上。 Abstract:The gene for human polypeptide chain elongation factor-1α(EEF1A)is a house-keeping gene which plays an important role in the process of protein synthesis.By means of comprehensive analysis in the database of Genbank,GDB and ect,we identify 4 retropseudogenes of EEF1A and finely localized to 4q25,7p15-21,9q34 and 19q13,respectively.