首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
阎冰  罗绍彬 《昆虫学报》1995,38(2):138-145
以新筛选的对鞘翅目,鳞翊目、双翅目均具毒性的B.t.Tml3-14菌株为材料,用HD-1、3370-1为参考菌株,比较了伴孢晶体蛋白的多肽组成,以及经三种昆虫肠道酶降解产生的抗酶多肽组分。SDS-PAGE分析表明:Tml3-14晶体蛋白含1 38kD、l 32kD主要成分和65kD次要我分。其晶体分别由三种昆虫肠道酶消化产生的毒性多肽,经生物测定,杀家蚕的毒性成分为68.5kD、59kD多肽;杀斜纹夜蛾毒性成分为71kD,67kD和59.6kD多肽;杀马铃薯瓢虫毒性成分为69kD、65kD多肽。它与HD01、3370-1晶体均有明显差异。  相似文献   

2.
花生根瘤菌类菌体经超声波破碎,TritonX-100溶解,正已烷-硫酸铵处理后,再经DEAE-纤维素和Sephacryl凝胶柱层析等纯化步骤,获得凝胶电泳纯的膜结合态氢酶,比活为71.4μmolH2mg-1Protmin-1,为类菌体吸H2活性的211倍。纯化的氢酶分子量为110kD。经SDS-PAGE后,呈现两个蛋白带,分子量分利为65kD和35kD。纯酶的Ni含量为0.62molNi/mol氢酶。在磷酸缓冲液中其活性的最适pH为6.5。DCIP、亚甲蓝、铁氰化钾、细胞色素C均可作为氢酶的电子受体,其中以DCIP为最适。  相似文献   

3.
与光系统Ⅱ颗粒结合的对DTT敏感的蛋白酶的纯化和性质   总被引:1,自引:0,他引:1  
菠菜光系统Ⅱ颗粒的1mol/LNaCl抽提液经butyl-Toyopearl650M疏水层析和DEAE-SephadexA-50柱层析分离得一种对DTT敏感的蛋白酶。用SDS-PAGE和Superose12凝胶过滤测得该酶的分子量为37kD,其为单体酶。该酶可降解18kD和24kD水溶性蛋白质,分别产生13.2kD、12kD、10.5kD和23kD、22kD、20kD片段,最适pH为8.0,对NaCl不敏感,对DTT和β-Me敏感。抑制实验表明该酶不属丝氨酸类蛋白酶。  相似文献   

4.
研究了对鞘翅目昆虫有毒效的5个苏云金杆菌菌株YM-03,Sph04-04,YK14-01,SH11-05,Sph16-01晶体蛋白的多肽组成及抗原特性,并以二龄柳叶甲虫为供试虫测定了它们的LC50,其中以YM-03的毒效最高,用琼脂糖凝胶电泳快速检测了五株菌的质粒,证明其质粒图型各不相同。  相似文献   

5.
利用PEG分级,DEAE离子交换层析,Bhue Sepharose拟亲和层析,MonoQ离子交换层析等手段,分离纯化直二氏藻甘油三磷酸(G-3-P)脱氢酶(EC1.1.1.8)得到比活为12.6u/mg的电泳纯的酶,并对此酶的生化特性进行了研究。4-20%非变性聚丙烯酰胺梯度凝胶电泳测得全酶分子量约为270kD,SDS-PAGE表明该酶只有一种分子量约为65kD的亚基,据此推测该酶应为同四聚体。酶  相似文献   

6.
何首乌(PolygonummultiflorumThunb.)叶Cu·ZnSOD经硫酸铵盐析、离子交换柱层析及葡聚糖凝胶过滤等步骤,被分离成两组SOD同工酶(SOD1,SOD2),它们被纯化到均一程度。SOD1分子量为32.4kD,亚基分子量为16.2kD,最适pH值为50,在60℃和65℃时的半衰期分别为14min和8min;SOD2分子量为305kD,亚基分子量为159kD,最适pH值为60,在60℃和65℃时半衰期分别为32min和16min,它由274个氨基酸残基组成,不含Cys、Tyr和Try。SOD1和SOD2每mol酶都含有2molCu和2molZn,它们在紫外区最大吸收波长均为275nm。  相似文献   

7.
草鱼出血病病毒多肽的基因定位   总被引:15,自引:3,他引:12  
用聚丙烯酰胺凝胶电泳分离纯化的草鱼出血病病毒GCHV873的基因组ds-RNA的11个片段,分别在麦胚无细胞翻译体系中进行翻译。其翻译产物经SDS-PAGE系统分析。结果表明,基因组片段1、2、3、4、5、和10分别编码病毒核心衣壳的结构多肽VP1、VP2、VP3、VP4、VP5和VP10,片段6和7分别编码病毒外层衣壳的结构多肽VP6和VP7。片段8和9分别编码52kD和41kD的多肽,片段11编码两种多肽,分子量分别为29kD和19.5kD,它们与病毒结构多肽无明显对应关系。病毒基因组与多肽大体是一一对应的关系。  相似文献   

8.
枸杞果实铁型超氧物歧化酶的纯化及性质   总被引:7,自引:1,他引:6  
枸杞果实Fe-SOD粗提液经硫酶铵盐析、离子交换柱层析及凝胶过滤,纯化到电泳单班点均一程度。纯化的Fe-SOD分子量为44.6kD,亚基分子量为22.0kD。金属元素分析表明,每分子酶含1个Fe原子。该酶在紫外区最大吸收值为278nm。H2O2明显抑制该酶活性,KCN对酶活性无影响。该酶氨基酸组成与高等植物和蓝绿藻的Fe-SOD相似,但它具有较高甘氨酸,酸性氨基酸与碱性氨基酸比值高于等植物而与低等  相似文献   

9.
纯化酶经聚丙烯酰胺凝胶电泳显示单一蛋白带,SDS-PAGE显示一条蛋自带,其亚基分子量为39.8kD。用SephacrylS-200凝胶过滤测得全酶的分子量为79.4kD,该酶由两个相同亚基组成。其表观Km为12mmol/L,Vmax为99.5mg还原糖mg-1proteinh-1。  相似文献   

10.
甘薯叶片蔗糖酶的分离纯化及其部分性质   总被引:11,自引:0,他引:11  
纯化酶经聚丙烯酰胺凝胶电泳显示单一蛋白带,SDS-PAGE显示一条蛋白带,其亚基分子量为39.8kD。用Sephacryl S-200凝胶过滤测得全酶的分子量为79.4kD,该酶由两个相同亚基组成。其表观Km为12mmol/L,Vmax为99.5mg还原糖mg^-1protein h^-1。  相似文献   

11.
12.
13.
14.
15.
It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

16.
Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

17.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

18.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

19.
20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号