中华鳖肝金属硫蛋白的分离、纯化及鉴定（英文）

金属硫蛋白(metallothionein,MT)是一类低分子量、富含半胱氨酸的金属结合蛋白.MT几乎广泛分布于所有生物,包括哺乳动物、两栖动物、鱼、植物、真菌和蓝细菌.不同生物金属硫蛋白理化特性和其氨基酸序列及中心片段的比较研究,对研究MT的结构和生物功能及生物的分子进化提供重要依据.哺乳动物MT研究较多,爬行动物鳖MT的研究尚属空白,本文报道鳖肝的金属硫蛋白.中华鳖 (Pelodiscus sinensis) 分别经皮下注射ZnSO4、CuSO4和CdCl2 溶液诱导后,取乙醇沉淀的肝脏无细胞提取液再经Sephadex G-50、DEAE-SepharoseCL-6B 及SephadexG-25凝胶过滤和离子交换柱层析分离,自鳖肝脏中分别获得Zn-MT、Cu-MT和Cd-MT,未经诱导的鳖肝脏中无MT.质谱和HPLC分析其分子量约为6 300 dalton.根据氨基酸组成分析,鳖肝脏MT含61个氨基酸残基,其中MT的典型氨基酸Cys含量占17%.Lys、Glu和Asp含量较高,而芳香族氨基酸和组氨酸含量极低.从紫外光谱特性分析,Zn-MT、Cu-MT、Cd-MT紫外吸收肩分别在220 nm、270 nm和250 nm.表明确为鳖肝脏MT.从氨基酸残基数和分子量看,鳖肝脏MT与哺乳动物MT类似;而从氨基酸组成和结合金属离子的量看,又与低等生物蚯蚓及酵母菌的MT类似.鳖MT的特性介于哺乳动物MT与低等生物MT之间,体现了鳖这种生物进化的特点.     

镉诱导家兔肝脏含锌金属硫蛋白的纯化及鉴定

预先给家兔皮下注射CdCl_2四次,取肝脏经匀浆、离心、乙醇沉淀后,通过Sephadex G-50凝胶过滤层析,DEAE Sepharose Fast Flow离子交换层析和Sephadex G-25层析柱脱盐,得到MT的两个“亚型”—MT-1和MT-2,对其进行鉴定,其紫外扫描图谱示在280和250nm处无吸收峰,而最大吸收在220nm处。MT-1和MT-2均不含镉和铜,而每分子结合6个锌。用简化巯基试剂测定,MT-1含18.8个巯基,MT-2含19.1个巯基;HPLC分析MT主要以单体存在,也有少量二聚体。氨基酸组成与Cd-MT一致。整个纯化过程采用示波极谱法和火焰原子吸收光谱法测锌含量。结果表明前者可代替后者。     

鼠肝中金属硫蛋白的纯化

旨在探索鼠肝中金属硫蛋白(MT)提取工艺并加以改进。按照经典方法工艺提取MT,用中空纤维柱超滤方法加以改进,依据MT自身特点进行分离和鉴定。结果显示,粗品符合MT特点:分子量在6.5kD左右;无280nm特征吸收峰,加酸后紫外吸收(200-300nm)肩峰消失;通过离子交换可以实现MT1、MT2的分离;通过原子吸收测定,含有锌、铜、镉3种金属,锌含量最高,具有重要的病理生理意义。因此,与其它方法比较,改进后方法更适宜实验室制备。     

柱状田头菇（茶薪菇）金属硫蛋白的分离纯化与特性研究

应用快速灌注色谱系统首次从经Cd^2 诱导的柱状田头菇(茶薪菇)Agrocybe Cylindracea(DC.:Fr:)R.Maoire菌丝体中分离得到一种镉结合蛋白。通过Sephadex G-75凝胶过滤层析,原子吸收光谱分析(AAS),巯基含量测定及紫外吸收光谱分析表明这种镉结合蛋白具有金属硫蛋白(metallothionein,MT)的理化性质：即分子量为6kDa、每分子MT含18个半胱氨酸残基并结合7个镉原子、具有镉硫金属簇的特征紫外吸收光谱,初步鉴定为茶薪菇Cd—MT。     

柱状田头菇(茶薪菇)金属硫蛋白的分离纯化与特性研究

应用快速灌注色谱系统首次从经Cd2+诱导的柱状田头菇(茶薪菇)Agrocybecylindracea(DC.:Fr:)R.Maoire菌丝体中分离得到一种镉结合蛋白。通过SephadexG-75凝胶过滤层析,原子吸收光谱分析(AAS),巯基含量测定及紫外吸收光谱分析表明这种镉结合蛋白具有金属硫蛋白(metallothionein,MT)的理化性质:即分子量为6kDa、每分子MT含18个半胱氨酸残基并结合7个镉原子、具有镉硫金属簇的特征紫外吸收光谱,初步鉴定为茶薪菇Cd-MT。     

柱状田头菇(茶薪菇)金属硫蛋白的分离纯化与特性研究*

应用快速灌注色谱系统首次从经Cd2+诱导的柱状田头菇(茶薪菇)Agrocybecylindracea(DC.:Fr:)R.Maoire菌丝体中分离得到一种镉结合蛋白。通过SephadexG-75凝胶过滤层析,原子吸收光谱分析(AAS),巯基含量测定及紫外吸收光谱分析表明这种镉结合蛋白具有金属硫蛋白(metallothionein,MT)的理化性质:即分子量为6kDa、每分子MT含18个半胱氨酸残基并结合7个镉原子、具有镉硫金属簇的特征紫外吸收光谱,初步鉴定为茶薪菇Cd-MT。     

Activation of glycolysis by zinc is diminished in hepatocytes from metallothionein-null mice

The influence of hepatic metallothionein (MT) and zinc (Zn) on glycolysis was investigated in primary cultures of mouse hepatocytes prepared from MT-normal (+/+) and MT-null (−/−) mice. In MT +/+ mice, a close relationship was observed between the Zn concentration in the incubation medium (10–150 μM), increased MT levels in the cells, and increased glycolysis (accumulation of lactate + pyruvate) over 24 h, with significant effects seen at physiological levels of Zn (10–25 μM). Hepatocytes from MT −/− mice had significantly lower basal rates of glycolysis and demonstrated increased glycolysis only at Zn concentrations of 50 μM or greater. The lactate: pyruvate ratio was higher in the MT +/+ hepatocytes. The oxidation of endogenous fatty acid (accumulation of the ketone bodies, 3-hydroxybutyrate and acetoacetate) was initially greater in the MT +/+ hepatocytes, although only MT −/− hepatocytes showed increased ketone body production in response to Zn. The 3-hydroxybutyrate: acetoacetate ratio was higher in the MT +/+ hepatocytes and increased with increasing Zn concentrations. Intracellular Zn accumulation was 60% greater in the MT +/+ hepatocytes, with approximately 80% of the extra Zn associated with MT. The results implicate MT-associated Zn rather than increased intracellular Zn per se in the regulation of hepatic carbohydrate metabolism.     

重组缣孢菌细胞色素P-450nor的性质研究

纯化的重组缣孢菌细胞色素P-450nor（recombinant fusarium oxysporum cytochrome P-450nor,rF·P-450nor）用于动力学研究. 测得米氏常数K_m(NO)和K_m(NADH)分别为0.128 mmol/L和0.208 mmol/L. V_max(N₂O)为11 363 min^-1. 光谱吸收特性研究表明：rF·P-450nor具有典型的血红素蛋白的特性,在413 nm有最大吸收峰. 加入还原剂Na₂S₂O₄时,最大吸收峰前移至405 nm. 与CO结合后,再加入还原剂Na₂S₂O₄时,在450 nm处表现最大吸收.与NO结合后,最大吸收峰移至430 nm附近. 这些光谱特征的变化与天然的F·P-450nor完全一致.     

豆壳过氧化物酶的电子吸收光谱性质

应用电子吸收光谱技术研究了豆壳过氧化物酶 ( EC1 .1 1 .1 .7)的不同氧化态电子吸收光谱 ,并与其它来源的过氧化物酶作了比较研究 .天然态酶的特征吸收峰位为 40 4 nm的 Soret带 ,638nm的α带和 50 8nm的β带 ,与过氧化氢反应可生成三类复合物 .复合物 ( Com )在 40 8、580、61 8和 655nm处出现特征吸收 ;复合物 ( Com )在 41 9、52 9和 556nm处显示特征吸收 ;复合物 ( Com )则于 41 8、543和 578nm处显示特征吸收 .天然态酶经连二亚硫酸钠还原则出现 435和 558nm的特征峰 ,与氰化钾作用在 42 2和 544nm处显示特征吸收 .氰化钾对该酶的抑制为竞争性抑制 ,其 Ki 值为 2 .4μmol/L.     

中华鳖肝金属硫蛋白的分离、纯化及鉴定

金属硫蛋白metallothionein,MT)是一类低分子量、富含半胱氨酸的金属结合蛋白。MT几乎广泛分布于所有生物,包括哺乳动物、两栖动物、鱼、植物、真菌和蓝细菌,不同生物金属硫蛋白理化特性和其氨基酸序列及中心片段的比较研究,对研究MT的结构和生物功能及生物的分子进化提供重要依据。哺乳动物MT研究较多,爬行动物鳖MT的研究尚属空白,本文报道鳖肝的金属硫蛋白,中华鳖（Pelodiscus sinensis)分别经皮下注射ZnSO4,CuSO4和CdCl2溶液诱导后,取乙醇沉淀的肝脏无细胞提取液再经SephadexG-50、DEAE-SepharoseCL-6B及SephadexG-25凝胶过滤和离子交换柱层析分离,自鳖肝脏中分别获得Zn-MT、Cu-MT和Cd-MT,未经诱导的鳖肝脏中无MT,质谱和HPLC分析其分子量约为6300dalton。根据氨基酸组成分析。鳖肝脏MT含61个氨基酸残基,其中MT的典型氨基酸Cys含量占17%。Lys,Glu和Asp含量较高,而芳香族氨基酸和组氨酸含量极低,从紫外光谱特性分析,Zn-MT、Cu-MT、Cd-MT紫外吸收肩分别在220nm、270nm和250nm。表明确为鳖肝脏MT。从氨基酸残基数和分子量看,鳖肝脏MT与哺乳动物MT类似;而从氨基酸组成和结合金属离子的量看,又与低等生物蚯蚓酵母菌的MT类似。鳖MT的特性介于哺乳动物MT与低等生物MT之间,体现了鳖这种生物进化的特点。     

Astragalar morphology of late Eocene anthropoids from the Fayum Depression (Egypt) and the origin of catarrhine primates

The phylogenetic relationships of the late Eocene anthropoids Catopithecus browni and Proteopithecus sylviae are currently a matter of debate, with opinion divided as to whether these taxa are stem or crown anthropoids. The phylogenetic position of Catopithecus is of particular interest, for, unlike the highly generalized genus Proteopithecus, this taxon shares apomorphic dental and postcranial features with more derived undoubted catarrhines that appear in the same region 1-2 Ma later. If these apomorphies are homologous and Catopithecus is a stem catarrhine, the unique combination of plesiomorphic and apomorphic features preserved in this anthropoid would have important implications for our understanding of the crown anthropoid morphotype and the pattern of morphological character transformations that occurred during the early phases of stem catarrhine evolution.Well-preserved astragali referrable to Proteopithecus, Catopithecus, and the undoubted early Oligocene stem catarrhine Aegyptopithecus have provided additional morphological evidence that allows us to further evaluate competing hypotheses of interrelationships among Eocene-Oligocene Afro-Arabian anthropoids. Qualitative observations and multivariate morphometric analyses reveal that the astragalar morphology of Proteopithecus is very similar to that of early Oligocene parapithecids and living and extinct small-bodied platyrrhines, and strengthens the hypothesis that the morphological pattern shared by these taxa is primitive within crown Anthropoidea. In contrast, Catopithecus departs markedly from the predicted crown anthropoid astragalar morphotype and shares a number of apomorphic features (e.g., deep cotylar fossa, laterally projecting fibular facet, trochlear asymmetry, mediolaterally wide astragalar head) with Aegyptopithecus and Miocene-Recent catarrhines. The evidence from the astragalus complements other independent data from the dentition, humerus and femur of Catopithecus that support this taxon's stem catarrhine status, and we continue to maintain that oligopithecines are stem catarrhines that constitute the sister group of a clade containing propliopithecines and Miocene-Recent catarrhines.     

中国兰科二新记录种

兰科植物资源调查是掌握地区兰科本底资料的基础,对研究兰科植物的地理分布和资源多样性具有重要意义。该文报道了分别产自中国西藏自治区墨脱县和巴宜区的石豆兰属(Bulbophyllum Thou.)中国分布新记录种——尼泊尔大苞兰(B.raskotii J.J.Verm.,Schuit.&de Vogel)和曲唇兰属[Panisea(Lindl.)Steud.]中国分布新记录种——林芝曲唇兰(P.panchaseensis Subedi)。此二新记录种均生长在海拔约2000 m的常绿阔叶林中的树干或岩壁上。此外,还提供了二新记录种的形态特征描述和彩色图片等信息,并附有国产曲唇兰属的分种检索表。该研究结果扩充了我国兰科植物的记录,为我国兰科植物多样性和保护研究提供了新资料。     

中国异极衣科地衣二新记录种

该文综合运用形态学、解剖学和化学等方法对山东大型地衣进行分类研究,发现了两个中国新记录种,即德氏蜂窝衣(Heppia despreauxii)和多孢小极衣(Lichinella myriospora)。德氏蜂窝衣隶属于蜂窝衣属(Heppia),生于光线充足且裸露的土壤上,主要识别特征为下皮层缺失、子实层IKI+蓝色;多孢小极衣隶属于小极衣属(Lichinella),生于干燥的钙质岩石上,主要识别特征为其子实层IKI+酒红色变为蓝色。该文对这两个中国新记录种进行了详细描述,与近似物种进行了对比讨论,并且提供了其地衣体、子囊盘及其解剖特征图片。同时,该文还补充报道了白棋盘蜂窝衣(Heppia solorinoides)的有性繁殖结构特征和数据。蜂窝衣属和小极衣属均为山东新记录属。以上研究结果为中国异极衣科(Lichinaceae)地衣研究提供基础资料。     

藏药多刺绿绒蒿种子萌发特性研究

多刺绿绒蒿(Meconopsis horridula)为罂粟科绿绒蒿属一年生草本植物,是一种极具观赏价值和药用价值的高山植物,目前处于濒危状态,因此研究多刺绿绒蒿种子的萌发特性对其种子育苗及人工栽培具有重要意义。为了提高多刺绿绒蒿的种子发芽率,该研究以多刺绿绒蒿的种子为材料,分析了不同消毒剂、浸种时间、温度和外源植物激素对种子萌发特性的影响。结果表明:(1)最适消毒方法为75%乙醇1 min+3%H2O25 min,最适浸种时间为24 h,最适温度和光照条件为20℃/10℃(光照12 h/黑暗12 h),用无菌水浸种后的种子发芽率为49.67%。(2) GA_3100～600 mg·L~(-1)和NAA 5～30 mg·L~(-1)可以提高种子的发芽率、发芽势和发芽指数,缩短发芽启动时间和发芽持续时间,对种子的萌发有促进作用。(3) 6-BA 5 mg·L~(-1)和10 mg·L~(-1)对种子的萌发有一定的促进作用,但不显著,6-BA浓度≥15 mg·L~(-1)则抑制种子的萌发。(4)用GA3500 mg·L~(-1)浸种后的种子发芽指标最好,发芽率、发芽势和发芽指数分别为69.67%、33.00%、4.51,种子的发芽起始时间和发芽持续时间分别为10.67 d、11.67 d。     

荨麻科三新种

该文描述了荨麻科三新种:(1)自中国重庆市发现的荨麻科荨麻属一新种,城口荨麻。此种与异株荨麻有亲缘关系,区别特征为此种的茎被少数刺毛,叶片多为心形,雄、雌花序均不分枝,瘦果在中央稍凹陷。(2)自中国广西发现的荨麻科赤车属一新种,来宾赤车。此种与特产云南东南部的富宁赤车相近缘,与后者的区别在于本种茎的毛开展或向上弯曲,叶片长椭圆形,基部斜楔形,雌花具3~4枚花被片,其中1~2枚较大花被片在背面顶端具一长筒状突起。(3)自缅甸北部发现的荨麻科楼梯草属一新种,克钦楼梯草。此种在体态上与骤尖楼梯草甚为相似,与后者的区别在于本种的每一茎节具正常叶和一退化叶,托叶狭披针状条形和无脉,雌总苞苞片无角状突起,雌小苞片较大,呈楔状长圆形,雌花具一小花被片,以及雌蕊具一宽倒卵球形柱头。     

scabrous Modifies Epithelial Cell Adhesion and Extends the Range of Lateral Signalling during Development of the Spaced Bristle Pattern in Drosophila

The role of scabrous (sca) in the evenly spaced bristle pattern of Drosophila is explored. Loss-of-function of sca results in development of an excess of bristles. Segregation of alternately spaced bristle precursors and epidermal cells from a group of equipotential cells relies on lateral inhibition mediated by Notch and Delta (Dl). In this process, presumptive bristle precursors inhibit the neural fate of neighbouring cells, causing them to adopt the epidermal fate. We show that Dl, a membrane-bound ligand for Notch, can inhibit adjacent cells, in direct contact with the precursor, in the absence of Sca. In contrast, inhibition of cells not adjacent to the precursor requires, in addition, Sca, a secreted molecule with a fibrinogen-related domain. Over-expression of Sca in a wild-type background, leads to increased spacing between bristles, suggesting that the range of signalling has been increased. scabrous acts nonautonomously, and we present evidence that, during bristle precursor segregation, Sca is required to maintain the normal adhesive properties of epithelial cells. The possible effects of such changes on the range of signalling are discussed. We also show that the sensory organ precursors extend numerous fine cytoplasmic extensions bearing Dl molecules, and speculate on a possible role for these structures during signalling.     

Stratigraphy, artefact industries and hominid associations for Sterkfontein, member 5

A revised stratigraphy for the early hominid site of Sterkfontein (Gauteng Province, South Africa) reveals a complex distribution of infills in the main excavation area between 2.8 and 1.4 m.y.a, as well as deposits dating to the mid to late Pleistocene. New research now shows that the Member 4 australopithecine breccia (2.8-2.6 Ma) extends further west than was previously thought, while a late phase of Member 4 is recognized in a southern area. The artefact-bearing breccias were defined sedimentologically as Member 5, but one supposed part of these younger breccias, the StW 53 infill, lacks in situ stone tools, although it does appear to post-date 2.6 Ma when artefacts first appear in the archaeological record. The StW 53 hominid, previously referred to Homo habilis, is here argued to be Australopithecus. The first artefact-bearing breccia of Member 5 is the Oldowan Infill, estimated at 2-1.7 Ma. It occupies a restricted distribution in Member 5 east and contains an expedient, flake-based tool industry associated with a few fossils of Paranthropos robustus. An enlarged cave opening subsequently admitted one or more Early Acheulean infills associated in Member 5 west with Homo ergaster. The artefacts attest to a larger site accumulation between ca. 1.7 and 1.4 Ma, with more intensive use of quartzite over quartz and a subtle but important shift to large flakes and heavier-duty tools. The available information on palaeoenvironments is summarized, showing an overall change from tropical to sub-tropical gallery forest, forest fringe and woodland conditions in Member 4 to more open woodland and grassland habitats in the later units, but with suggestions of a wet localized topography in the Paranthropus -bearing Oldowan Infill.     

表皮葡萄球菌SarA对atlE、lipA和zinC基因表达调控的研究

表皮葡萄球菌 (Staphylococcus epidermids) 是一种条件致病菌，SarA(Staphylococcal accessory regulator A)是该菌中一个全局性调控因子，它控制着细胞中许多与毒性相关的基因表达. 报道了SarA在转录水平直接调控atlE、lipA和zinC基因的表达. RT-PCR和lacZ报告基因的分析结果显示，在表皮葡萄球菌ATCC35984中，SarA对atlE (自溶酶基因) 表达起负调控作用，而对lipA (脂肪酶基因) 和zinC (膜相关锌金属蛋白酶基因) 的表达则有正调控作用. 生物信息学分析表明，SarA控制atlE，lipA和zinC 3种基因表达可能是通过与被调控基因上游的特定DNA序列的结合来实现的，该DNA结合区保守并富含AT碱基. 根据已报道的金黄色葡萄球菌中SarA的结合位点序列，利用Omiga软件分析并推测了SarA结合atlE，lipA和zinC的可能区域. 基于SarA是一种多功能的毒素相关调控因子，结果提示，SarA能调控众多因子，可以作为防治表皮葡萄球菌感染的一个药物筛选靶点.     

中国星文衣属地衣型真菌的分类研究

星文衣属(Sarcographa)隶属于真菌界(Fungi)、子囊菌门(Ascomycota)、茶渍纲(Lecanoromycetes)、厚顶盘目(Ostropales)、文字衣科(Graphidaceae),该属地衣体为壳状,子囊盘为放射分支状,多具子座,子囊含8孢子,子囊孢子褐色,横隔透镜型或亚砖壁型,主要分布于热带亚热带地区。该文通过形态学、解剖学、化学与分子生物学等方法进行该属分类学研究,共报道了中国该属9种,其中变黄星文衣[Sarcographa flavescens(Dal-Forno & Eliasaro)L. W. Chen & Z. F. Jia]为新组合(≡ Phaeographis flavescens Dal-Forno & Eliasaro); 曲线星文衣[Sarcographa labyrinthica (Ach.)Müll. Arg. ]为中国大陆新记录种。同时,该文对近似属拟星文衣属(Sarcographina)的1物种——异孢拟星文衣[Sarcographina heterospora(Nyl.)Z. F. Jia & Lücking]进行了描述,并提供了10个物种的特征提要及与其近似种的区别特征,并编制了分种检索表。该研究为中国地衣型真菌生物多样性研究提供了基础资料。     

OsIMA1增强水稻对镉逆境的适应性

铁(Fe)是植物生长发育所必需的营养元素而镉(Cd)是对植物有害的元素且对植物Fe和Cd的吸收存在拮抗作用。OsIMA是一类正调控水稻Fe吸收的一类小肽,其过表达可以促进Fe的积累。为探究OsIMA是否参与水稻对Cd胁迫的适应性,该研究以水稻为研究材料,利用荧光定量PCR分析了OsIMA基因的表达水平,通过遗传转化和CRISPR/Cas9基因编辑技术构建了OsIMA1过表达植物和ima1突变体植物,评估了OsIMA1过表达和突变体植物在Cd逆境条件下的株高,并利用电联耦合等离子体质谱法测量了根和地上部的Fe和Cd含量。结果表明:(1)Cd处理后,OsIMA1和OsIMA2的转录水平上调。(2)OsIMA1过表达植物比野生型植物对Cd胁迫更耐受。(3)ima1功能缺失突变体比野生型植物对Cd胁迫更敏感。(4)OsIMA1过表达植株根系的Cd含量较高,而ima1突变体植株地上部的Cd含量较高。综上所述,OsIMA1通过限制Cd从根向地上部的转运以增强水稻对Cd逆境的适应能力,该研究结果为定向培育耐Cd作物提供了理论参考。