尿素改善SDS-PAGE分离小分子肽的效果

目的：探讨尿素对Tricine—SDS—PAGE系统分离小分子蛋白的影响。方法：利用常规SDS-PAGE和Tricine-SDS-PAGE分离小分子肽,比较不同组成的分离胶的分离效果。结果：调整聚丙烯酰胺凝胶的分子组成,使丙烯酰胺和甲叉双丙烯酰胺的交联度为5．05％,能够改善小分子肽的分离效果。加入36％的尿素比加入甘油可以更有效分离1kD的小肽。但尿素胶聚合太快影响分离效果。结论：尿素改善SDS—PAGE分离小分子肽的效果,制作尿素胶时,宜采用低浓度的AP和TEMED使凝胶慢速聚合。     

小麦低分子量麦谷蛋白亚基组成研究

利用改良的两步一向SDS—PAGE(two—step one—dimensional SDS—PAGE)分析了几种小麦低分子量麦谷蛋白亚基(LMW-GS)组成。70％热乙醇提取总谷蛋白,11％分离胶进行第一步SDS—PAGE分离．电泳1h后切取顶端1cm胶条并置于巯基乙醇溶液进行还原,还原后的胶条于11%～16．5％的梯度胶进行第二步SDS—PAGE分离。结果显示。两步一向SDS—PAGE可以彻底除去清蛋白、球蛋白和醇溶蛋白对LMW—GS分离的背景干扰。提高LMW—GS的分辨率。对几种小麦低分子量麦谷蛋白亚基分析表明：LMW-GS组合比HMW—GS更为丰富,每种小麦含有2～5种B亚基,2～4种C亚基．B、C亚基的总数量为4～8种。     

有效分离1kDa小肽的Tricine-SDS-PAGE方法

为了建立能有效分离 1kDa的特小分子肽的Tricine SDS PAGE方法 ,调整分离胶中聚丙烯酰胺凝胶的分子组成 ,使致密胶中丙烯酰胺和双丙烯酰胺的交联度为 5 %,并加入 36 5 %的尿素 ,用于分离小至 1kDa的小分子肽 ,并与常规的SDS PAGE和先前报道的Tricine SDS PAGE相比较。结果改进的致密胶可以有效分离分子量小至 1kDa的小肽 ,明显优于常规的SDS PAGE和现有的Tricine SDS PAGE方法。     

乳抗氧化肽的分离纯化与结构鉴定

本文检测了不同分子量范围的WPI(乳清分离蛋白)酶解物的抗氧化活性,结果表明各个组分显示出不同的抗氧化活性,其中分子量小于5 kDa的组分最强。采用凝胶过滤色谱对分子量小于5 kDa的WPI酶解物进行分离,抗氧化活性强的组分继续采用RP-HPLC进行纯化。通过MALDI-TOF-MS与氨基酸组成分析鉴定该活性肽为His-Ile-Arg。     

天麻多肽的分离纯化研究

目的：研究生物多肽对生物机体的生命活动有益或生理作用。方法：对天麻（Gastrodiae elata B1．）初提液两次超滤（3kDa和1kDa超滤膜）,凝胶过滤和快速蛋白液相色谱（FPLC）分离纯化,以及反相高效液相色谱（RP-HPLC）对目标肽进行分析检测。结果：由Sephadex G-15葡聚糖凝胶柱层析分析肽液,得到各肽组分的相对分子质量分布范围。FPLC和RP-HPLC分析第二峰结果表明,此多肽组分分别只由一种肽组成。结论：此多肽相对分子质量在2500Da左右,具有很好的亲水性。     

种子中Puroindoline蛋白的SDS-PAGE分析

Puroindolne蛋白是小麦中特殊的Triton X-114可溶性蛋白质,对小麦籽粒硬度有着决定性的影响.从二倍体、六倍体小麦材料及小麦近缘种粗山羊草成熟种子中提取Puroindoline蛋白,就对该蛋白的SDS-PAGE及染色条件进行了优化和讨论,建立了浓缩胶T(凝胶浓度)为4、C(交联度)为2.6、电泳电压为128 V;分离胶T为13.5、C为2.6、电泳电压240 V,分离胶电泳时间1.5 h的结果稳定且重复性好的优化的SDS-PAGE条件.同时为降低电泳染色的实验成本,简化实验步骤,用蓝染法代替常用的银染法,并获得了良好的效果,为小麦中Puroindoline蛋白质的进一步研究奠定了实验基础.     

竹叶青(Trimeresurus stejnegeri)蛇毒凝血酶样酶的分离纯化及其理化性质的研究

用CM—Sephadex C—25分离竹叶青粗毒,再经DEAE—Sephadex A—50和CM—Sephadex C—25纯化得到凝血酶样酶组分Ⅰ。用DEAE—Sephadex A—50分离竹叶青粗毒,再经DEAE—Sepharose CL—6B纯化得到凝血酶样酶组分Ⅱ。用聚丙烯酰胺凝胶电泳和SDS—聚丙烯酰胺凝胶电泳鉴定,组分Ⅰ在两种电泳中均为一条带; 组分Ⅱ在两朴电泳中均为二条带,经切割后鉴定证明组分Ⅱ的二条带都是凝血酶样酶。组分Ⅰ的分子量为54,500,由261个氨基酸残基组成,其中Asp和Glu含量较高,含14％中性己糖,13.1％己糖胺和14.7％唾液酸,等电点为3.5,在280nm处的消光系数为E_(1cm)~(0.1％)=0.855。组分Ⅱ的分子量分别为54,000和47,000。经凝胶电泳分离后用过碘酸—Schiff's试剂染色,证明组分Ⅰ和组分Ⅱ都是糖蛋白。     

罗氏沼虾中等足类AGH类似物的分离与鉴定

从2l30尾性成熟的雄性罗氏沼虾体内采集雄性腺体(AG),匀浆后,分离沉淀等电点为4.5左右的多肽,用十二烷基磺酸钠-聚丙烯酰胺凝胶电泳法收集分子量从17kDa至l8kDa的多肽条带.进一步应用高效液相色谱、无胶筛分高效毛细管电泳、基质辅助激光解吸电离飞行时间质谱、高效液相色谱-电喷雾电离-质谱等技术进行分离与鉴定.结果显示,主要组分的分子量为17436±110u,在等电点4.5的条件下分离得到的罗氏沼虾AG组分中,以分子量17480u的多肽组分为主,与等足类ArmadillidiumvulgareAGH的分子量相似,暂称为等足HAGH类似物.     

一种改进的β淀粉样蛋白的电泳分离方法

目的：建立一种简便、快捷的β淀粉样蛋白的电泳分离方法。方法：比较以往报道的各种低分子量蛋白的电泳分离方法,对电泳缓冲液系统、分离胶和浓缩胶的浓度,电泳程序等进行了优化,结果：用改进的Two Phases Tris-Trincine-SDS-PAGE可以简单,快速,清地分离β淀粉样蛋白,结论：新建立的Two Phases Tris-Trincine-SDS-PAGE是一种较好地分离β淀粉样蛋白和其它超低分子量蛋白或多肽的电泳方法。     

无胶筛分毛细管电泳在分析苹果发育时期转变蛋白质变化规律中的应用

对无胶筛分毛细管电泳体系的筛分介质浓度、缓冲体系的离子强度、分离电压、进样量及温度等条件进行了优化, 最终确定最佳分离条件为7.5% Dextran, 7.5%丙三醇, 0.15 mol.L-1 TB, 0.1% SDS, 分离电压23.5 kV, 进样量1.5 ps i×90秒, 温度25°C。应用此方法对金冠×红玉苹果杂种后代韧皮部蛋白质进行测定, 得到了多个与阶段转变相关的蛋白质, 在韧皮部50节上, 有分子量为5.0 kDa的特异蛋白质出现, 分子量为24.5 kDa的蛋白质含量在阶段转变过程中明显升高。     

Tanaidacea (Crustacea) of the north-east Atlantic: the subfamily Pseudotanainae (Pseudotanaidae) and the family Nototanaidae

Sixteen species of the tanaidacean subfamily Pseudotanainae and three of the family Nototanaidae have been recorded from shallow and deep waters in the north-east Atlantic. Six new species of Pseudotanais , and the new genera Mystriocentrus, Parapseudotanais and Bathytanaissus are described. The species Pseudotanais affinis is re-described, and a cladistic analysis of the 'affinis' species-group is presented. Pseudotanais is a eurybathic genus and individuals of this taxon are common in the region. The Nototanaidae is poorly represented in the deep-sea, and the present record is the first for the Northern Hemisphere.     

Tanaidacea (Crustacea) of the north-east Atlantic: the subfamily Pseudotanainae (Pseudotanaidae) and the family Nototanaidae

Sixteen species of the tanaidacean subfamily Pseudotanainae and three of the family Nototanaidae have been recorded from shallow and deep waters in the north-east Atlantic. Six new species of Pseudotanais, and the new genera Mystriocentrus, Parapseudotanais and Bathytanaissus are described. The species Pseudotanais affinis is re-described, and a cladistic analysis of the ‘affinis’ species-group is presented. Pseudotanais is a eurybathic genus and individuals of this taxon are common in the region. The Nototanaidae is poorly represented in the deep-sea, and the present record is the first for the Northern Hemisphere.     

New anthracenedione derivatives: Interaction with DNA and biological effects

Two anthracenedione derivatives [1 - (ω - diethylaminopropylamido) - 4 - hydroxy - 9,10 - anthracenedione hydrochloride (I) and 1 - (ω - diethylamino-propylamido) - 2 - methoxy - 4 - hydroxy - 9,10 - anthracenedione hydrochloride (II)], having an electron-rich planar chromophore and an amino-substituted side chain, have been synthesized. Their binding ability to DNA was investigated by means of spectroscopic, equilibrium dialysis and fluorescence measurements. Their inhibition efficiency on nucleic acid synthesis was also evaluated both in mouse and human cells. Our results indicate that, in comparison with adriamycin, compound I shows a slightly weaker complexation ability to DNA, while compound II interacts with DNA at a substantially lower level. These data match quite well with the biological response on the inhibition of DNA and RNA synthesis exhibited by the above mentioned compounds; in fact compound I is slightly less efficient than adriamycin and about ten times more efficient than compound II. The close relationship between the results of physicochemical and biological studies is discussed.     

拟除虫菊酯的杀虫活性和温度的关系

除了戊酸醚酯对苜蓿蚜呈弱的正温度系数外,杀灭菊酯、二氯苯醚菊酯、氯氰菊酯、溴氰菊酯、氟氰菊酯及百树菊酯,都呈负温度系数。杀灭菊酯、戊酸醚酯、二氯苯醚菊酯、氯氰菊酯、溴氰菊酯和氟氰菊酯,对梨网蝽全部呈正温度系数。氯氰菊酯对粘虫呈负温度系数,杀灭菊酯、戊酸醚酯、二氯苯醚菊酯和溴氰菊酯都呈正温度系数。杀灭菊酯和溴氰菊酯对粘虫卵也呈正温度系数。杀灭菊酯对小菜蛾的杀虫活性,受温度的影响不明显,而戊酸醚酯则呈负温度系数。杀灭菊酯和戊酸醚酯对蚊幼呈正温度系数,而二氯苯醚菊酯则呈负温度系数。     

Skeletal ultrastructure and phylogeny of cyclostome bryozoans

Recent research on the ultrastructure of the calcareous skeleton in the bryozoan order Cyclostomata is summarized and updated, based on field emission SEM studies of 87 species. Six fundamental ultrastructural fabrics are recognized which differ in the crystallographic orientations, shapes and prevailing growth directions of the constituent crystallites. During the growth of individual walls a succession of fabrics is secreted, defining a fabric suite. Five fabric suites are described in interior walls and four in exterior walls. Nine ultrastructural characters were combined with 37 other skeletal characters in a PAUP analysis of the relationships between 28 post-Palaeozoic cyclostomes chosen to include representatives of all suborders. A single tree of length 142 steps was found. Comparison of tree statistics for three categories of characters showed ultrastructural characters to be more homoplastic than zooidal characters, and the latter more homoplastic than colonial characters. Rooting the tree on the paleotubuliporine Cuffeyella gave four transitions from fixed- to free-walled organization and no reversals. With respect to the five extant suborders of cyclostomes, this first, preliminary analysis implies that Rectangulata and Cancellata are monophyletic groups, whereas Articulata are diphyletic, and both Tubuliporina and Cerioporina paraphyletic.     

Phylogenetic relationships in the iguanid lizard genus Liolaemus: multiple origins of viviparous reproduction and evidence for recurring Andean vicariance and dispersal

Phylogenetic relationships within the iguanid lizard genus Liolaemus are investigated using 1710 aligned base positions (785 phylogenetically informative) of mitochondrial DNA sequences, representing coding regions for eight tRNAs, ND2, and portions of ND1 and COL Sixty new sequences ranging in length from 1736 to 1754 bases are compared with four previously reported sequences. Liolaemus species form two well-supported monophyletic groups of subgeneric status, Liolaemus and Eulaemus. These subgenera appear to have separated at least 12.6 million years ago based on the amount of molecular evolutionary divergence between them. Hypotheses that species occurring in the Andes, west of the Andes, and east of the Andes, each comprise distinct monophyletic groups are independently rejected statistically. The shortest estimate of phylogeny suggests mat Liolaemus originated either in the Andes or the eastern lowlands. Numerous evolutionary shifts have occurred between the Andes, and the eastern and western lowlands, suggesting recurring vicariance and dispersal. Species occurring at high elevations or high latitudes usually have viviparous reproduction. Depending on whether parity mode is considered reversible in Liolaemus , the most parsimonious reconstruction supports at least six independent origins of viviparity or at least three gains followed by three losses of viviparity among die 60 Liolaemus lineages examined.     

The composition of the caudal skeleton of teleosts (Actinopterygil: Osteichthyes)

The diural caudal skeleton of teleostean actinopterygians develops phylogeneticaily and ontogenetically from a polyural skeleton. The reduction of the polyural anlage to four, three, two or fewer centra in the adult caudal skeleton takes different pathways in different genera (e.g. compare Elops and Albula) and groups of teleosts. As a result, ural centra are not homologous throughout the teleosts. By numbering the ural centra in a homocercal tail in polyural fashion, one can demonstrate these and the following differences. The ventral elements (hypurals) always occur in sequential series, whereas the dorsal elements (epurals and uroneurals) may alter like the ural centra. The number of epurals, five or four in fossil primitive teleosts, is reduced in other primitive and advanced teleosts, but the same epurals are not always lost. The number of uroneurals, seven in fossil teleosts, is reduced in living teleosts, but it has not been demonstrated that the first uroneural is always derived from the neural arch of the same ural centrum. The landmark in the homocercal tail is the preural centrum I which can be identified by (1) bifurcation of the caudal artery and vein in its ventral element, the parhypural, (2) its position directly caudal to the preural centrum (PU2) which supports the lowermost principal caudal ray with its haemal spine, (3) carrying the third hypaxial element ventral to the course of arteria and vena pinnalis, and (4) by carrying the first haemal spine (parhypural) below the dorsal end of the ventral cartilage plate. The study of the development of the vertebral column reveals that teleosts have different patterns of centrum formation. A vertebral centrum is a complete or partial ring of mineralized, cartilaginous or bony material surrounding at least the lateral sides of the notochord. A vertebral centrum may be formed by arcocentrum alone, or arcocentral arcualia and chordacentrum, or arco-, chorda- and autocentrum, or arcocentral arcualia and autocentrum. This preliminary research demonstrates that a detailed ontogenetic interpretation of the vertebral centra and of the caudal skeleton of different teleosts may be useful tools for further interpretations of teleostean interrelationships.     

Skeletomuscular anatomy of the harvestman Leiobunum aldrichi (Weed, 1893) (Arachnida: Opiliones: Palpatores) and its evolutionary significance

Skeletal muscles of the North American harvestman Leiobunum aldrichi are exhaustively surveyed and compared with other chelicerates to clarify the evolutionary morphology and phylogenetic relationships of arachnids. Representatives of 104 muscle groups are described and illustrated, and their possible functions are proposed. Comparisons of the feeding apparatus of L. aldrichi with that of other opilions, especially Sim (Cyphophthalmi) and Acromares (Laniatores), and two scorpion genera ( Centruroides, Pandinus ) indicate that the pharyngeal apparatus in L. aldrichi is derived and that its ability to accommodate large food particles is a secondary rather than primitive condition. Comparisons reveal several possible synapomorphies between Opiliones and Scorpiones suggesting that these orders may be sister groups. Apparently unique synapomorphies include an extrinsic cheliceral muscle that arises from the carapace and inserts on the second cheliceral article (deutomerite); an epistome divided into distal and proximal parts by a transverse sulcus; pharyngeal dilator muscles supported by a peripharyngeal skeleton formed by one dorsomedial and two ventrolateral epistomal processes, the latter also with muscular attachments to the endosternite; a specialized preoral chamber (stomodieca) derived from extensions (coxapophyses) of the coxae of the pedipalp and first two leg pairs; internal processes associated with the coxapophyses that serve, in part, as an attachment for muscles operating the coxa-trochanter joints, and lateral endosternal suspensor muscles that insert on the arthrodial membrane between the leg coxae. These are the first observations providing explicit support for an Opiliones-Scorpiones clade.