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1.
D1/D2/Cyt—559复合物的共振拉曼光谱 总被引:1,自引:0,他引:1
光系统Ⅱ(PSⅡ)反应中心D1/D2/Cytb-559复合物在488nm处激发的共振拉曼谱显示4个主要谱带,其峰位分别在1532(vl)1165(v2)1010(v3)和970(v4)cm^-1处,表明PSⅡ反应中心结合的β-胡萝卜素分子是全反式构型。D1/D2/Cytb-559复合物在色素抽提液的拉曼光谱也显示4个主要的拉曼峰,其中v4谱带的强度急剧下降,说明PSⅡ反应中心内部结合的β-胡萝卜素 相似文献
2.
光系统Ⅱ(PSⅡ)反应中心D1/D2/Cytb-559 复合物在488 nm 处激发的共振拉曼光谱显示4 个主要谱带,其峰位分别在1532(υ1)、1165(υ2)、1010(υ3)和970(υ4) cm - 1处,表明PSⅡ反应中心结合的β-胡萝卜素分子是全反式构型。D1/D2/Cytb-559 复合物的色素抽提液的拉曼光谱也显示4 个主要的拉曼峰,其中υ4 谱带的强度急剧下降,说明PSⅡ反应中心内部结合的β-胡萝卜素分子与抽提液中自由的β-胡萝卜素分子的构象不同,而与光合细菌反应中心内部的类胡萝卜素分子的构象相似,其共轭多烯链的平面也处于扭曲状态 相似文献
3.
PSⅡ反应中心D1/D2/Cytb559 复合物的圆二色(CD)光谱在红区有一个反向带,其正峰在680 nm ,负峰在660 nm 处。光破坏后,该反应中心复合物的CD信号明显下降,而且当正峰完全消失后,负峰仍然存在,说明该反应中心的CD信号不仅来源于原初电子供体P680,而且可能来源于其它色素分子 相似文献
4.
光系统Ⅱ反应中心D1/D2/Cytb559复合物中去镁叶绿素a的光照破坏 总被引:1,自引:0,他引:1
高等植物在强光照射下,光合作用受到抑制。光抑制的分子机理已成为目前光合作用研究中最活跃的研究领域之一[1]。由于叶绿体内色素和蛋白分子很多,其中包含有许多与光破坏不直接相关的组分,因此很难确定具体哪个分子受到破坏。用只含少数色素和多肽分子的光系统Ⅱ(PSⅡ)反应中心D1/D2/Cytb559复合物[2]可以解决这个问题,现已证明用光照射该复合物能引起原初电子供体P680的破坏[3,4],并且是一个多步反应[5],同时还发现有组氨酸残基的光照破坏[6,7],当存在电子受体的情况下反应中心内部β-c… 相似文献
5.
通过多频相位调制法测得菠菜叶绿体光系统Ⅱ(PSⅡ)反应中心D1/D2/cytb559复合物的荧光衰减包括4个组分,其寿命分别大约为1、6、24和73ns,所占整个荧光的比例依次为5%、34%、35%和26%。而寿命为6ns的组分来源于与电荷分离不相关的chla分子,寿命为1ns的组分所占的比例很小,其来源不清楚。其中两个长寿命组分都与样品的光化学活性相关,但彼此又是不相关的,很可能来源于电荷分离后的两个不同的重组过程。 相似文献
6.
线二色光谱(LD)是研究色素分子在光合膜上空间取向和排布的重要手段。采用低温(100K)吸收光谱和线二色光谱技术研究光系统Ⅱ核心复合物CP47/D1/D2/Cyt b-559中色素分子的空间取向。结果表明,在光系统Ⅱ核心复合物CP47/D1/D2/Cyt b-559中680nm处有吸收的叶绿素分子Qy跃迁与光合膜平面平行。β-胡萝卜素分子有两种不同的空间取向,其中在470和505nm处有吸收的β- 相似文献
7.
紫色光合细菌反应中心的三维空间结构的解析,极大地推动了光合作用电子传递机理的研究。现已清楚光合细菌反应中心内部存在着两条电子传递支路[1—2],由于高等植物光系统Ⅱ(PSⅡ)反应中心D1蛋白和D2蛋白与光合细菌反应中心L亚基和M亚基的一级结构具有很大的相似性,推测PSⅡ反应中心内部也可能存在类似的结构。从高等植物叶绿体中分离纯化的PSⅡ反应中心D1/D2/Cytb559复合物具有原初电荷分离活性[3],其中含有4—6个Chla分子,2个Pheoa分子,1—2个β-胡萝卜素分子,它们是否像光合细菌… 相似文献
8.
菠菜叶绿体光系统Ⅱ反应中心D1/D2/Cyt b-559复合物的荧光衰减包括4个组分,其寿命分别大约为1.0ns,5.9ns,24ns和73ns,所占整个荧光的量子产率依次为0.05,0.34,0.35和0.26。这些不同寿命组分的荧光发射光谱相互重叠在一起,稳态光谱只显示1个发射峰。根据相调荧光测定的“硬件”分析方法,通过选择检测器的相角,可以选择性地把各个寿命组分的荧光分别滤掉。如果5.9ns 相似文献
9.
光系统Ⅱ反应中心D1/D2/Cyt b559 复合物对光照十分敏感。不仅色素分子,而且多肽链上的氨基酸残基(如组氨酸和甲硫氨酸)均会受到破坏。光照同时引起D1 和D2 蛋白的降解。在SDS聚丙烯酰胺多肽电泳图谱上,D1/D2 二聚体的含量增多,同时有一条分子量大约为41 kD的新带出现。在光照后的暗放置过程中,氨基酸组成不再变化,但D1 和D2 蛋白的降解及大分子量片段的产生仍继续进行。对组氨酸和甲硫氨酸的破坏与D1、D2 蛋白的降解关系进行了初步的分析,推测在光破坏过程中,D1 和D2 蛋白也许发生了化学断裂和共价交联作用 相似文献
10.
菠菜叶绿体光系统Ⅱ反应中心D1/D2/cyt b559长寿合荧光组分的来源 总被引:1,自引:0,他引:1
通过多频相位调制法测得菠菜叶绿体光系统Ⅱ反应中心D1/D2/cyt b559复合物的荧光衰减包括4个组分,其寿命分别大约为1、6、24和73ns,所占整个荧光的比例依次为5%、34%、35%和26%。而寿命为6ns的组分来源于与电荷分离不相关的chl a分子,寿命为1 ns的组分所占的比例很小,其来源不清楚。其中两个长寿合组分都与样品的光化学活性相关,但彼此又是不相关的,很可能来源于电荷分离后的两 相似文献
11.
Tang Chong-qin Kuang Ting-yun Yu Zhen-bao Lu Rong-he Peng De-chuan Tang Pei-song Li Cheng-yong 《植物学报(英文版)》1994,36(4)
Photosystem Ⅱ reaction center D1/D2/Cytochrome b559 complex loses its bound secondary electron acceptor QA and QB during isolation and purification. The artificial plastoquinone can reconstitute with the complex. The reconstitution of decyl-plastoquinone (DPQ) with D1/D2/Cytochrome b559 complex results in a decrease of the fraction of the two long lived fluorescence decay components (24 ns and 73 ns) coupled with photochemical activities to the total fluorescence yields, as well as a decrease of the total fluorescence intensity and a blue-shift of maximum emission wavelength. These results suggest that as the electron acceptor of reduced Pheo, DPQ restricts the charge recombination of P680+ Pheo-, and the two long lived fluorescence decay components (24 ns and 73 ns) come from the recombination. Although DPQ reconstitution has little effect on the susceptibility of Chi a to photodamage, β-carotene can easily be photodamaged after DPQ reconstitution. This is probably related to the physiological function of β-carotene. 相似文献
12.
Kuang Ting-yun Yu Zhen-bao Tang Chong-qin Lu Rong-he Peng De-chuan Tang Pei-song 《植物学报(英文版)》1993,35(3)
Histidine residue content of photosystem Ⅱ reaction center D1/D2/cytochrome b559 complex decreased by about 26% after illumination. The result suggests that some histidine residues are damaged by illumination. The damage of histidine residues may be related to the changes of the spectra properties during the incubation in the dark following preillumination of the reaction center complex. 相似文献
13.
Allakhverdiev SI Hayashi H Nishiyama Y Ivanov AG Aliev JA Klimov VV Murata N Carpentier R 《Journal of plant physiology》2003,160(1):41-49
The presence of 1.0 mol/L glycinebetaine during isolation of D1/D2/Cytb559 reaction centre (RC) complexes from photosystem II (PSII) membrane fragments preserved the photochemical activity, monitored as the light-induced reduction of pheophytin and electron transport from diphenylcarbazide to 2.6-dichlorophenol-indophenol.-Glycinebetaine also protected the D1/D2/Cytb559 complexes against strong light-induced damage to the photochemical reactions and the irreversible bleaching of beta-carotene and chlorophyll. The presence of glycinebetaine also enhanced thermotolerance of the D1/D2/Cytb559 complexes isolated in the presence of 1.0 mol/L betaine with an increase in the temperature for 50% inactivation from 29 degrees C to 35 degrees C. The results indicate an increased supramolecular structural stability in the presence of glycinebetaine. 相似文献
14.
采用26S rRNA基因D1/D2区系统发育分析的方法对CICC(中国工业微生物菌种保藏管理中心)保藏的15株白地霉(Geotrichum candidum)菌种进行复核鉴定。系统发育分析结果表明15株白地霉属于地霉属的成员,且形成两个系统发育分支,系统发育上最接近Galactomyces geotrichum NRRLY-17569T,与其同源性为96.3%~98.3%。15株白地霉26S rRNA基因D1/D2区序列显著不同于地霉属的模式种及其它种,可能代表地霉属的两个新种,但这一结论尚需进一步的实验去证实。 相似文献
15.
On the basis of affinity differences for spiperone, two binding sites for [3H](+/-)-2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene ([3H]ADTN) in the rat brain could be distinguished: "D3" with a low and "D4" with a high affinity for spiperone. Evidence is provided that D3 and D4 sites are related to high agonist affinity states of the D1 and D2 dopamine receptors, respectively. Various well-known selective D1 and D2 agonists and antagonists showed potencies at these sites in agreement with this hypothesis. A comparison of the Bmax values for [3H]ADTN binding to D3 and D4 sites with the numbers of D1 receptors (labelled by [3H]SCH 23390) and of D2 receptors (labelled by [3H]spiperone), both in the striatum and in the mesolimbic system, indicated that under the conditions used for 3H-agonist binding experiments, both populations of D1 and D2 receptors were converted to their high agonist affinity states to a considerable, although different extent. In fact, when competition experiments with [3H]spiperone were performed under the conditions otherwise used for [3H]ADTN binding experiments (instead of the conditions usually used for antagonist binding), substantial shifts of the displacement curves of 3,4-dihydroxyphenylethylamine (dopamine) and ADTN toward higher affinities were observed. A comparison of the effects of various agonists and antagonists in the [3H]ADTN binding experiments and in functional tests revealed a significant correlation between their potencies at D4 binding sites and at D2 receptors modulating the release of [3H]acetylcholine from striatal slices. However, in the situation of the D1/D3 pair, when the measurement of adenylate cyclase activity was taken as a functional test for D1 receptors, agonists were more active in the binding than in the functional test, whereas for many antagonists the opposite was found. The results are discussed with regard to the classification and functional aspects of brain dopamine receptors. 相似文献
16.
S/D灭活血浆内脂包膜病毒及病毒灭活血浆的研究 总被引:1,自引:0,他引:1
研究磷酸三丁酯(TNBP)/Triton X-100对血浆内脂包膜病毒的灭活效果。用VSV病毒和Sindbis病毒作指示病毒,加入血浆后再加磷酸三丁酯/Triton X-100,观察病毒的滴度变化及对血浆蛋白的影响。结果发现终浓度各为1%的磷酸三丁酯/Triton X-100在60min内可以灭活血浆内的两种指示病毒,而血浆蛋白的组成和功能变化很小。经层折、超滤后血浆内磷酸三丁酯和Triton X-100的残余量分别低于5μg/ml,表明S/D处理血浆的安全性和治疗作用都很好,其制剂冰冻血浆或冻干血浆可用于临床治疗凝血因子缺乏症,或用作血容量扩张剂。 相似文献
17.
Febo M González-Rodríguez LA Capó-Ramos DE González-Segarra NY Segarra AC 《Journal of neurochemistry》2003,86(2):405-412
Estrogen potentiates behavioral sensitization to cocaine in the female rat by mechanisms that remain undetermined. In this study, functional receptor autoradiography was used to investigate estrogen modulation of D2/D3 receptor-induced G protein activation in components of the reward pathway of female rats treated acutely and repeatedly with cocaine. Rats were ovariectomized and given an empty (OVX group) or estradiol benzoate-filled (OVX-EB group) implant. After a week, animals received a daily saline or cocaine injection (15 mg/kg, i.p.) for 5 days, and again on day 13. Animals were killed, and brains were removed and cryosectioned. D2/D3-stimulated [35S]guanosine 5'-(gamma-thio) triphosphate (GTPgammaS) binding was assessed in the cingulate cortex area 2 (Cg2), striatum (STR), nucleus accumbens (NAc) and ventral tegmental area (VTA). OVX-EB rats showed more [35S]GTPgammaS binding in the Cg2 and lower binding in the VTA than OVX rats; in the VTA this effect was reversed by a single cocaine injection. Repeated cocaine administration had opposite effects in OVX and OVX-EB rats. [35S]GTPgammaS binding was decreased in the Cg2, NAc and STR of OVX-EB rats, and increased in OVX rats. The present results support the hypothesis that cocaine-induced changes in D2/D3 receptor activation are regulated by estrogen. These data suggest that changes in D2/D3 receptor function represent one mechanism by which estrogen regulates behavioral sensitization to cocaine. 相似文献
18.
时玲甘桂萍金治娟顾惠平张文华 《现代生物医学进展》2011,11(13):2532-2534
目的:应用胎儿脐血流检测仪测定脐动脉S/D值探讨导致脐血流S/D比值升高的主要原因。方法:对2009年9月~2010年12月在我院进行产前检查的1919例孕28~42周的孕妇检测胎儿脐动脉血流(S/D)。结果:异常组108例的脐带因素、胎儿窘迫、羊水过少及妊高征的发生率均明显高于正常组,两者比较差异有显著性(P<0.05)。结论:脐动脉S/D比值增高可及早地警示和发现胎儿宫内缺氧情况,指导临床提早采取干预和处理措施,提高围产保健质量。 相似文献
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20.
The D1/D2 domain of the large-subunit rDNA of the yeast species Clavispora lusitaniae is unusually polymorphic 总被引:2,自引:0,他引:2
Lachance MA Daniel HM Meyer W Prasad GS Gautam SP Boundy-Mills K 《FEMS yeast research》2003,4(3):253-258
Ten different versions of the D1/D2 divergent domain of the large-subunit ribosomal DNA were identified among interbreeding members of the yeast species Clavispora lusitaniae. One major polymorphism, located in a 90-bp structural motif of the D2 domain, exists in two versions that differ by 32 base substitutions. Three other polymorphisms consist of a two-base substitution, a two-base deletion, and a single-base deletion, respectively. The polymorphisms are independent of one another and of the two mating types, indicating that the strains studied belong to a single, sexually active Mendelian population. Several strains were heterogeneous for one or more of the polymorphisms, and one strain was found to be automictic and capable of producing asci on its own by isogamous conjugation or by bud-parent autogamy. These observations suggest circumspection in the use of sequence divergence as the principal criterion for delimiting yeast species. 相似文献