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1.
研究了SD-5菌株伴孢晶体结构多钛组成和抗原特性,分析了氨基酸组成并进行了糖蛋白的检测,结果表明:SD-5晶体蛋白主含Mw135000、Mw65000两条多肽,另见有一Mw240000的弱带,不同方法处理的样品,电泳图谱有一定差异;SD-5晶体蛋白抗血清与其晶体抗原形成两条沉淀线,而与7216、HD-1形成一条沉淀线。 相似文献
2.
花毛茛植株再生途径的离体调控 总被引:5,自引:0,他引:5
花毛茛的叶接种子MS+2,4-Dlmg/L+NAAl+6-BA2的培养基上,3-4周后,形成愈伤组织,将愈伤组织分别转移到MS+2,4-D1-2和MS+6-BA1.5-2.5的培养基上,培养4周左右,从愈伤组织表面通过胚状体发生和不定芽发生两条途径形成植株;而将叶接种于MS+6-BA2+NAA0.2-0.5+LH500的培养基上,则可在叶和叶片的过渡区不经过愈伤组织直接分化出芽并形成植株。 相似文献
3.
分离兔角膜上皮和皮肤表皮,提取水溶性蛋白质,采用SDS-PAGE以及IEF/SDS-PAGE技术对其组成进行分析研究,发现兔角膜上皮存在5种主要特异性水溶性蛋白质,其分子量和等电点分别为:Mr68200,pI7.5;Mr61700,pI5.1;Mr51300,pI7.6;Mr36300,pI8.9和Mr25700,pI5.7。 相似文献
4.
探讨了培养基成分、培养时间、高渗缓冲液成分和pH、溶菌酶浓度以及酶解温度和时间对苏云金杆菌SD-5菌株原生质体形成和再生的影响;结果表明,SD-5菌株原生质形成和再生的最佳条件组合为:PBG培养基、30℃培养14h再活化5h,以SMMpH6.5作酶解缓冲液,溶菌酶浓度0.6mg/ml,34℃处理60min。 相似文献
5.
应用葡聚糖凝胶柱层纯化了水牛梭形住内孢子虫缓殖子抗原,并应用SDS-PAGE分析了缓殖子可溶性粗抗原及纯化抗原的蛋白组分,结果表明:缓殖子可溶性粗抗原含有14种蛋白成分,分子量范围为45.9-71.2KD,经过SephadexG-100柱层析纯化扣的抗原在SDS-PAGE图谱上显示5条蛋白带,分子量分别为58KD,61KD,64KD,66KD,70KD。 相似文献
6.
制备了5′端共价连接EDTA的寡聚核苷酸与生命金属的螯合物ODN-5′-EDTAM(n+),其中M(n+)为Fe(Ⅱ),Co(Ⅱ)或Cu(Ⅱ);分析、计算了这3个螯合物形成的最佳pH值范围,ODN-EDTAFe(Ⅱ)为pH5.8~8.6,ODN-EDTACo(Ⅱ)为PH4.6~8.1,ODN-EDTACu(Ⅱ)为pH3.4~5.7;在此条件下,剪切反应必须的Mg2+并不与Fe(Ⅱ),Co(Ⅱ)或Cu(Ⅱ)竞争EDTA,也不会形成沉淀;讨论了ODN-EDTAM(n+)切割DNA双链的反应机理:修饰寡核苷酸通过氢键在DNA双链的大沟结合形成三链体,在O2和还原剂DTT作用下,Fe作为催化剂,产生羟基自由基,氧化糖环,切割EDTAFe(Ⅱ)附近的DNA双链. 相似文献
7.
碳陶瓷复合材料抗氧化性能研究 总被引:2,自引:0,他引:2
将SiC、B4C等碳化物陶瓷粉末与碳粉混合,采用热压烧结工艺制备碳陶瓷复合材料。对碳质量分数wC分别为0.1,0.2,0.3,0.4,0.5的5种碳陶瓷复合材料,在800℃、1000℃和1300℃高温空气中的氧化性能进行了研究。结果表明,碳陶瓷复合材料在wC<0.2时,抗氧化性很好;在wC>0.3时,氧化速率加快。氧化后试样表面的XRD谱和SEM下的微观结构研究表明,氧化过程中碳陶瓷复合材料晶粒表面形成了SiO2和B2O3固溶体薄膜,阻止了材料的进一步氧化。 相似文献
8.
用牦牛肝片吸虫四种抗原分别制备四种抗血清,其ESISA效价 1:800,1:1600,1:3200和1:800.SDS-PAGE电泳区带组分分别为25,24,18和9条带;免疫印迹结果,各种抗清与相庆抗原作用的主要抗原成份分别为5,10,7和3;四种抗原中存在的共同抗原为17.2kD;特征抗原HA为29.9kD,SA为27.2kD的24.3kD;正常兔血清与各个抗原间均未出现免疫反应。 相似文献
9.
通过DEAE-CelluloseDE-52和DEAE-SePhadexA-50离子交换层析等提纯步骤,对解脂假丝酵母胞外脂肪酶进行了纯化,得到了层析纯样品,比活提高27.4倍,得率11%.该酶反应最适温度为40℃;最适PH为7.5;等电点约在PH4.5~5.0之间;8℃以下存放,酶活力损失较少,30℃以上存放,酶活力有明显损失.金属离子Sr2+,Ba2+,Zn2+和Mg2+对该酶的激活作用为Sr2+>Ba2+>Zn2+>Mg2+.Cu2+和Na+对酶活性有抑制作用.NaN3对保持酶活性有重要作用. 相似文献
10.
SO^2—4/TiO2/ZSM—5催化剂催化性能的研究 总被引:4,自引:0,他引:4
以浸渍沉淀负载法制备了SO^2-4/TiO2/ZSM-5分子筛催化剂,用XRD,IR,DTA,TG,NH3-TPD,ICP等对催化剂的物化性能进行表征,考察了它对酯化反应制乙酸丁酯的催化活性。结果表明;催化剂含TiO2为6.0wt%,SO^2-4为3.2wt%,在最佳条件下,乙酸的转化率达98.8%,选择性为100T〉达到以硫酸为催化剂的催化活性。 相似文献
11.
A region of SV40 large T antigen can substitute for a transforming domain of the adenovirus E1A products 总被引:41,自引:0,他引:41
SV40 large T antigen contains a small region of amino acid sequence, conserved among the papovaviruses, that shows considerable similarity to conserved domain 2 of the adenovirus E1A oncogene, a domain which plays an important role in the E1A transforming functions. To learn whether the analogous SV40 T antigen sequences could substitute functionally for E1A domain 2, a chimaeric gene was constructed, coding for T antigen amino acid residues 101 to 118 in place of E1A domain 2. The resulting product showed much of the activity of the wild-type E1A products. It induced proliferation of primary BRK cells and cooperated with the ras oncogene to transform these cells fully. In addition, the chimaeric protein coprecipitated two cellular proteins whose specific binding to the E1A products depends on the presence of domain 2. The activity of the chimaeric product suggests that a similar functional unit exists in the transforming proteins of both SV40 and adenovirus, and that these proteins may exert their cell growth regulating effects through similar mechanisms. 相似文献
12.
Nucleotide sequence of the gene coding for the major protein of hepatitis B virus surface antigen. 总被引:60,自引:0,他引:60
DNA extracted from hepatitis B virus Dane particles has been cloned in bacteria using a plasmid vector. A full-length clone has been examined by restriction endonuclease analysis, and the nucleotide sequence of an 892-base pair fragment from cloned hepatitis B viral DNA encoding the surface antigen gene is reported. The amino acid sequence deduced from the DNA indicates that the surface antigens is a protein consisting of 226 amino acids and with a molecular weight of 25,398. The portion of the gene coding for this protein apparently contains no intervening sequences. 相似文献
13.
用子囊菌SD-9701菌株能产生红色素的特性,进行了无盐培养基筛选的研究,从而避免了在培养基中含有金属离子而对色素的影响,并有利于色素的进一步分离、提取、提纯等工作的开展.结果表明,子囊菌SD-9701菌株产红色素的最佳无盐培养基配方为:大米粉20g/L,发酵粉5g/L,H2O 1000mL. 相似文献
14.
ECBP21 is an extracellular calmodulin-binding protein which was first detected and purified from extracellular extracts of
suspension-cultured cells of Angelica dahurica. The purified protein was electroblotted onto PVDF membrane and the amino acid sequences from 1 to 20 were determined. Using
degenerate oligonucleotides of the sequence, a full-length cDNA coding for ECBP21 was isolated by a combination of RT-PCR
and 5′-RACE cloning. The cDNA contains 947 nucleotides and codes for a precursor protein of 216 amino acids. The N-terminal
1–25 amino acid sequence is a predicted signal peptide and the other 26–216 amino acid sequence is a mature peptide. The 26–45
amino acid sequence shows identity with the N-terminal amino acid sequence of purified ECBP21 from Angelica dahurica. The fragment of encoding the mature protein was cloned into pET-28b(+) and transformed into E. coli BL21(DE3). A protein with relative molecular mass 21 ku was expressed in E. coli. Using a biotinylated-CaM gel overlay technique, the expression protein was tested for its ability to bind CaM. The results
indicated that the expression protein is a Ca2+-dependent CaM-binding protein. Thus, these results further defined the cDNA clone for ECBP21. This work laid a foundation
for elucidating biological functions of ECBP21 by using molecular biological means. 相似文献
15.
An interspecies conserved antigen ofPlasmodium falciparum containing clusters of asparagine residues
An interspecies conservedPlasmodium asparagine rich antigen, designated as ARK26, was isolated by immunoscreeningP. falciparum genomic DNA expression library with mouse convalescent anti-P. yeolii serum. Partial DNA sequence analysis reveals that ARK26 contains clusters of asparagines and no randomly repeated amino acid
sequence motifs are observed. A 65×103 GST fusion protein is expressed by recombinant plasmid PGEX-5X-1 (ARK26) inE. coli C strain ABLE-K. Computer programs predict that two asparagine rich regions are among the possible antigenic epitopes of
p37 encoded by ARK26. Interestingly, the sequence of ARK26 displays significant similarity to yeast and several other species’
mitochondrial genes, and its possible function is discussed.
Supported by a fellowship offered by International Center for Genetic Engineering & Biotechnology(ICGEB)
Ma Donghui: born in 1969, Graduate student 相似文献
16.
Escherichia coli contains three DNA polymerases that differ in their size, ability to interact with accessory proteins and biological function. Monomeric DNA polymerase I (Pol I) has a relative molecular mass (Mr) of 103,000 (103K) and is involved primarily in the repair of damaged DNA and the processing of Okazaki fragments; polymerase II is of Mr 120K, and polymerase III has a Mr of 140K, is responsible for the replication of the DNA chromosome and is just one of several proteins that are required for replication. DNA polymerases from bacteriophage as well as those of eukaryotic viral and cellular origin also differ with respect to their size and the number of associated proteins that are required for them to function in replication. However, the template-directed copying of DNA is identical in all cases. The crystal structure of the large proteolytic fragment of Pol I shows that it consists of two domains, the larger of which contains a deep crevice whose dimensions are such that it can bind duplex DNA. The T7 polymerase consists of two subunits, the 80K gene 5 protein and the host-encoded 12K thioredoxin of E. coli. We show here that there is an amino acid sequence homology between at least eight polypeptide segments that form the large cleft in the Klenow fragment and polypeptides in T7 DNA polymerase gene 5 protein, suggesting that this domain evolved from a common precursor. The parts of the Pol I and T7 DNA polymerase molecules that bind the DNA substrate appear to share common structural features, and these features may be shared by all of these varied DNA polymerases. 相似文献
17.
ECBP21 is an extracellular calmodulin-binding protein which was first detected and purified from extracellular extracts of suspension-cultured cells of Angelica dahurica. The purified protein was electroblotted onto PVDF membrane and the amino acid sequences from 1 to 20 were determined. Using degenerate oligonucleotides of the sequence, a full-length cDNA coding for ECBP21 was isolated by a combination of RT-PCR and 5′-RACE cloning. The cDNA contains 947 nucleotides and codes for a precursor protein of 216 amino acids. The N-terminal 1-25 amino acid sequence is a predicted signal peptide and the other 26-216 amino acid sequence is a mature peptide. The 26-45 amino acid sequence shows identity with the N-terminal amino acid sequence of purified ECBP21 from Angelica dahurica. The fragment of encoding the mature protein was cloned into pET-28b(+) and transformed into E. coli BL21(DE3). A protein with relative molecular mass 21 ku was expressed in E. coli. Using a biotinylated-CaM gel overlay technique, the expression protein was tested for its ability to bind CaM. The results indicated that the expression protein is a Ca2+- dependent CaM-binding protein. Thus, these results further defined the cDNA clone for ECBP21. This work laid a foundation for elucidating biological functions of ECBP21 by using molecular biological means. 相似文献
18.
对3株导入外源基因的转基因小球藻(Chlorella ellipsoidea SD-0702,C.ellipsoidea SD-0705,C.ellipsoidea SD-0706)进行生长动力学、藻粉产量和产油脂能力的研究,并且与野生型小球藻(C.ellipsoidea SD-0701)进行比较.结果表明:(1)SD-0705的比生长速率最大,代时最短,与SD-0706的比生长速率均高于SD-0701,SD-0702则低于SD-0701;(2)SD-0705和SD-0706的藻粉得率均高于SD-0701,SD-0702则较野生型小球藻低;(3)SD-0705的油脂产量最高,为0.470 g/L,高于SD-0701,其他2株转基因小球藻的油脂产量均低于野生型小球藻.由此筛选出SD-0705作为藻粉和油脂的高产藻株. 相似文献
19.
研究了一种结构复杂、具有特殊用途的新型有机硅非离子表面活性剂(商品名SD-5)在溶液表面上的吸附特性和对二甲基黄(DMAB)的增溶作用,并考察了各种电解质时SD-5溶液的浊点和增溶作用的影响. 相似文献
20.
SV2和SVOP都是大鼠中包含有12个跨膜结构域的突触小泡蛋白.笔者从人类大脑的cDNA文库中分离得到了一个类似于大鼠突触小泡蛋白SV2和SVOP的人类新基因的全长cDNA序列,它包含一个含有1 646个核苷酸的开放阅读框,编码一个含548个氨基酸的蛋白质.生物信息学分析表明:该基因定位在第12号染色体的12q24.12区域.Northern杂交结果表明:该基因只在人类大脑组织中表达,且与无脊椎动物线虫、疟蚊和果蝇的同源基因有50%的氨基酸同源性,与脊椎动物大鼠和小鼠的同源基因有90%以上的氨基酸同源性. 相似文献