一个适用于分离光系统Ⅱ的凝胶电泳系统

用一高分辨率的凝胶电泳系统从延长破碎时间的蓝藻类囊体膜增溶物中分离出１４条绿色的带。按照电泳迁移率的增加顺序,自上而下分别是ＣＰＩａ,ＣＰＩｂ,ＣＰＩｃ,ＣＰＩｄ,ＣＰＩｅ,ＣＰＩｆ,ＣＰＩｇ,ＣＰＩｈ,ＣＰａ１,ＣＰａ２,ＣＰａ３,ＣＰａ４,ＣＰａ５和ＦＣ。ＣＰａ１,ＣＰａ２,ＣＰａ３,ＣＰａ４和ＣＰａ５５种叶绿素蛋白复合体的吸收光谱相似,它们在蓝区的吸收峰位子４３６ｎｍ,而红区的吸收峰则位于６７０—６７３ｎｍ附近。它们的低温荧光发射光谱亦很相似,其荧光发射峰都位于６８５ｎｍ处。因此它们都属于光系统Ⅱ叶绿素ａ蛋白复合体．跟传统电泳相比,该系统对光系统Ⅱ的分离能力提高了１．５倍。     

野生和黄化大麦类囊体膜色素蛋白的分离和比较

用混和去垢剂（ＳＤＳ、ＯＧ）增溶和温和电泳方法,对野生和黄化大麦的叶绿体类囊体膜进行了色素蛋白复合体组成的分离和比较,并结合ＳＤＳ－聚丙烯酰胺凝胶电泳对类囊体膜蛋白进行了鉴定。结果表明,黄化大麦类囊体膜色素蛋白组分中,ＬＨＣ Ⅱ和ＬＨＣ Ⅰ的含量都较野生型大麦明显减少;并讨论了黄化大麦类囊体膜色素蛋白含量的减少与其光合速率降低的关系。     

一个高分辨率的凝胶电泳系统及其从蓝藻中分离的叶绿素蛋白复合体

用一高分辨率的凝胶电泳系统从蓝藻类囊体膜中分离出至少１３ 个清晰的叶绿素带,它们是ＣＰＩａ、ＣＰＩｂ、ＣＰＩｃ、ＣＰＩｄ、ＣＰＩｅ、ＣＰＩｆ、ＣＰＩｇ、ＣＰＩｈ、ＣＰａ１、ＣＰａ２、ＣＰａ３、ＣＰａ４ 和ＦＣ,其分辨率较传统方法高出１ 倍多。ＣＰＩａ—ＣＰＩｈ ８ 种组分有相同的吸收光谱,其红峰和蓝峰的位置分别位于６７６ ｎｍ 和４３６ ｎｍ 处。它们都属于光系统Ｉ叶绿素蛋白复合体。ＣＰａ１—ＣＰａ４ ４ 种组分的光谱性质亦基本相同,其吸收峰的位置分别位于６７０—６７２ ｎｍ 和４３６ ｎｍ 处,而低温荧光发射峰的位置都位于６８５ ｎｍ 处。它们都属于光系统Ⅱ叶绿素蛋白复合体     

光破坏的光系统Ⅱ反应中心D1／D2／Cytb559复合物的CD光谱

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     

(E160A)和(E160D)天花粉蛋白两种突变体晶体结构研究

培养了（Ｅ１６０Ａ）ＴＣＳ和（Ｅ１６０Ｄ）ＴＣＳ的单晶。在ＭＡＲＲｅｓｅａｒｃｈ面探测器系统上分别收集了０．１９３ｎｍ和０．２０ｎｍ分辨率的Ｘ射线衍射数据。数据处理用ＭＡＲＳＣＡＬＥ程序系统完成。用同晶差值Ｆｏｕｒｉｅｒ法解析了突变体的晶体结构,结构修正利用Ｘ－ＰＬＯＲ程序。修正结果,晶体学Ｒ因子分别为０．１７５,０．１７９,键长和键角的ＲＭＳ偏差分别为０．００１１ｎｍ和２．４５７°,０．００１３ｎｍ和２．６７５°。在这两个突变体的结构中均未见到Ｇｌｕ１８９侧链方向的改变。通过对（Ｅ１６０Ａ）ＴＣＳ和（Ｅ１６０Ｄ）ＴＣＳ的结构比较,说明（Ｅ１６０Ｄ）ＴＣＳ活性低于（Ｅ１６０Ａ）ＴＣＳ的原因：这可能是由于在（Ｅ１６０Ｄ）ＴＣＳ中Ｔｙｒ１１１和Ｔｙｒ７０的侧链都具有较大的运动性,使它们与腺嘌呤碱基的芳香堆垛作用减弱,从而导致活性的降低     

商品果胶酶中endo—PG的分离纯化及其部分性质研究

以Ａ．ｎｉｇｅｒ来源的果胶酶为材料,经过ＣＭ－Ｓｅｐｈａｄｅｘ Ｃ－５０及Ｓｅｐｈａｄｅｘ Ｇ－１００两步骤分离化得到电泳均一的ｅｎｄｏ－ＰＧ１及ｅｎｄｏ－ＰＧ２其亚基分子量分别为３５ｋＤ及３７ｋＤ,含糖量为１１．２２％及８．３％,最大此吸收峰分别在２７４ｎｍ及２６９ｎｍ处,氨基酸组成分析结果表明Ｇｌｙ含量较高,Ｍｅｔ含量较低,不含Ｃｙｓ,并且酸性氨基酸含量高于碱性氨基酸,圆二色谱结果表明二级结构     

玉米花粉32kD蛋白的纯化及性质

利用丙酮粉、硫酸铵分段盐析及离子交换层析技术,从玉米花粉细胞质中分离纯化了一种３２ｋＤ的可溶性蛋白,其ＧＴＰａｓｅ活性大于ＡＴＰａｓｅ。ＳＤＳ－ＰＡＧＥ表明达银染电泳纯。等电聚焦电泳测得等电点为５．２５。免疫印迹鉴定表明该蛋白与抗牛脑动蛋白或动力蛋白的抗体无免疫交叉反应。最大紫外吸收波长为２８２ｎｍ,ＣＤ谱分析说明具有球蛋白特征。     

玉米花粉32kD蛋白的纯化及性质

利用丙酮粉,硫酸铵分段盐析及离子交换层析技术,从玉米花粉细胞质中分离纯化了一种３２ｋＤ的可溶性蛋白,其ＧＴＰａｓｅ活性大于ＡＴＰａｓｅ。ＳＤＳ－ＰＡＧＥ表明达银染电泳纯。等电聚焦电泳测得等电点为５．２５。免疫印迹鉴定表明该蛋白与抗牛脑动蛋白或动力蛋白的抗体无免疫交叉反应。最大紫外吸收波长为２８２ｎｍ,ＣＤ谱分析说明具有球蛋白特征。     

甲基单胞菌Methylomonas sp.GYJ3中甲烷单加氧酶还原酶组分的纯化和性质

Ｍｅｔｙｌｏｍｏｎａｓｓｐ．ＧＹＪ３菌的甲烷单加氧酶（ＭＭＯ）粗酶提取液经ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ阴离子交换层析、ＳｅｐｈａｄｅｘＧ－１００凝胶过滤层析和ＤＥＡＥ－ＴＳＫｇｅｌＨＰＬＣ分离纯化出ＭＭＯ还原酶组分．经ＨＰＬＣ分析,纯度大于９５％,纯化倍数为４．４,加入至ＭＭＯ羟基化酶和调节蛋白Ｂ的体系中表现比活为２２８ｎｍｏｌ环氧丙烷每分钟毫克蛋白．ＳＤＳ－ＰＡＧＥ电泳表明还原酶由一种亚基组成,分子量４２ｋＤ．ＩＣＰ－ＡＥＳ测定还原酶的Ｆｅ含量为１．８３ｍｏｌＦｅ每ｍｏｌ蛋白．ＵＶ－Ｖｉｓ光谱表明还原酶除２８０ｎｍ蛋白质特征峰外在４６０ｎｍ有最大吸收峰,且Ａ２８０ｎｍ／Ａ４６０ｎｍ为２．５０,与其它黄素一铁硫蛋白相似,推测还原酶可能含一个ＦＡＤ辅基和Ｆｅ２Ｓ２中心．在厌氧条件下,还原酶能够和ＮＡＤＨ作用,ＵＶ－Ｖｉｓ光谱分析表明还原酶４６０ｎｍ处特征吸收峰消失,说明在ＭＭＯ催化过程中还原酶接受ＮＡＤＨ的电子．ＤＥＡＥ－ＳｅｐｈａｒｏｓｅＣＬ－６Ｂ阴离子交换层析分离出调节蛋白Ｂ,部分纯化的调节蛋白Ｂ的分子量大约在２０ｋＤ,它能够提高ＭＭＯ比活性４０倍,ＭＭＯ还原酶和调节蛋白Ｂ单独存在时不具有ＭＭＯ     

光系统Ⅱ反应中心CP47／D1／D2／Cyt b—559复合物中色素分子空？…

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－     

十个甾体皂甙元的~(13)C NMR谱

本文报道心不甘(Tupistra aurantiaca Wall et Backer)的十个甾体皂甙元:△~5一系列的3-epiruscogenin(1),3-epi-ruscogenin(2),tupisgenin(3)和aurantigenin(4),5-β-系列的ranmogenin A(5)、B(6)、C(7)、D(8)、△~(25(27))—pentrogenin(9)和1β、2β、3β、4β、5β、7α-hexahydroxy-spirost-25(27)-en-6-one(10)的~(13)C NMR的归属和解析的研究结果。     

心磷脂-细胞色素C体系CD谱的研究

 线粒体内膜中含有特异的心磷脂是细胞色素C氧化酶活性的必需脂。本工作测定了心磷脂脂质体对细胞色素C溶液园二色(CD)谱的影响,发现心磷脂可引起血色素铁的氧化,并使其轴向配位场强的对称性下降。提示心磷脂可能参与酶和底物之间的电子转移过程。     

Determination of the degree of acetylation of chitin materials by 13C CP/MAS NMR spectroscopy

¹³C CP/MAS NMR spectroscopy has been shown to be a powerful tool to quantify the degree of acetylation of chitin and chitosan. In order to optimise the parameters which afford quantitative ¹³C cross-polarisation magic-angle spinning NMR spectra, a detailed relaxation study has been carried out on selected chitin and deacetylated chitin samples. A relaxation delay of 5 s and a contact time of 1 ms have been found to yield quantitative NMR spectra of samples with deacetylation degree values of 0.68 and 0.16. The measured spin-lattice relaxation times in the rotating frame, T_1ρH, are in the range 6.4–8.9 ms for chitin and 4.3–7.3 ms for deacetylated chitin, while T_CH values for both samples are very similar and range from 0.03 to 0.19 ms. Spin-counting experiments indicate that, within experimental error, all carbon is detected by NMR indicating that the samples studied contain no (or very few) paramagnetic centres.     

Dissymmetric calix[4]arenes: Optical resolution of some conformationally fixed derivatives

Various possibilities to obtain intrinsically chiral calix[4]arenes are discussed. The enantiomers of three 1,3-dietheresters and one monoether compound derived from dissymmetric calix[4]arenes with C₄ symmetry were separated by HPLC using chiral stationary phases and characterized by their CD spectra. © 1993 Wiley-Liss, Inc.     

CHAPS对M_(412)的动力学和共振拉曼光谱的影响

研究了表面活性剂CHAPS对紫膜中菌紫质在光循环过程中M_(412)的衰减速率及质子泵功能的影响.光循环中间体M_(412)快、慢衰减组分的衰减速率及质子衰减速率均受到CHAPS的影响,综合激光拉曼光谱对M_(412)和其它光循环中间体相对含量的测定,表明CHAPS对紫膜的影响是通过影响其膜脂完整的液晶结构,而使紫膜光循环动力学过程及质子泵功能发生变化的.     

Structural and mode of action studies on bio-active molecules

The technique of nuclear Overhauser effect difference spectroscopy allows the determination, from¹H nuclear magnetic resonance spectra, of those protons in a structure which are near in space to a selected, irradiated proton. The experiment is extremely powerful in the determination of structure in solution, and is sufficiently precise often to give stereochemical detail. The method was used in determination of the structures of the antibiotics of the teicoplanin complex (members of the vancomycin group), and the principles are briefly illustrated. Additionally, nuclear magnetic resonance pulse sequences can be used to edit¹³C spectra (separate the spectrum into four spectra, containing C, CH, CH₂, and CH₃ carbons), and this technique also aided the structure elucidation of the teicoplanin complex. Finally, it is emphasised that nuclear Overhauser effect difference spectroscopy can be used to determine the molecular details of drug binding sites, and an example is given.     

Excitation Energy Transfer in Cyanobacteria Synechocystis Embedded in Polymer Film and Partially Bleached by Polarized Irradiation

The polarized absorption, photoacoustic, fluorescence emission, and fluorescence excitation spectra of whole cells of cyanobacteria Synechocystis sp. embedded in a polymer film were measured. The bacteria cells, as it follows from anisotropy of absorption and fluorescence spectra, were even in a non-stretched polyvinyl alcohol film oriented to a certain extent. The measurements were done for such film in order to avoid the deformation of cyanobacteria shapes. Part of the samples was bleached by irradiation with strong polarized radiation with electric vector parallel to the orientation axis of cells. The anisotropy of photoacoustic spectra was higher than that of absorption spectra and it was stronger changed by the irradiation. Polarized fluorescence was excited in four wavelength regions characterised by different contribution to absorption from various bacteria pigments. The shapes of emission spectra were different depending on wavelength of excitation, polarization of radiation, and previous irradiation of the sample. The fluorescence spectra were analysed on Gaussian components belonging to various forms of pigments from photosystems (PS) 1 and 2. The results inform about excitation energy transfer between pools of pigments, differently oriented in the cells. Energy of photons absorbed by phycobilisomes was transferred predominantly to the chlorophyll of PS2, whereas photons absorbed by carotenoids to chlorophylls of PS1.     

用光谱技术鉴定植物色素突变体

1983年我国报道了从γ-射线处理的“矮杆齐”大麦中得到了一株黄绿色的突变体1832C[1]。本文用光谱技术对该突变体的光合色素成分进行了鉴定。1　材料和方法　　材料为六棱裸大麦“矮杆齐”和由该品种大麦诱变形成的黄绿色突变体1832C(Mb1832C),以及作为对照的缺失Chlb的突变体大麦Chlorina-f2[2]都于3月初播种于实验田中。　　每个样品取30g新鲜的叶片,先用自来水后用蒸馏水冲洗干净。把洗净的叶片摊放在干净的纱布上吸干表面水分,剪碎,加入100mL预冷的含有0.4mol/L山梨醇、0.1mol/LTris-HCl(pH7.6)的缓冲液,用组织捣碎机先慢速捣碎1…     

冬种绿肥和秸秆还田对双季稻区土壤团聚体和有机质官能团的影响

为探讨外源有机物料在提升土壤有机碳和改良土壤肥力中的作用机理,依托中国农业科学院衡阳红壤实验站的长期定位试验,研究了冬种绿肥和秸秆还田模式(CK,冬闲;MV,冬种紫云英;S,早稻秸秆全量还田;DS,早、晚稻秸秆全量还田;SMV,冬种紫云英+早稻秸秆全量还田;DSMV,冬种紫云英+早、晚稻秸秆全量还田)对土壤团聚体和有机质官能团的影响。结果表明: 双季稻土壤超大团聚体(>2 mm)和大团聚体(0.25～2 mm)含量最多,为72.1%～81.8%,且两者中有机碳含量高达12.1～20.7 g·kg^-1,占总有机碳的22.7%～59.0%。水稻土中有机物官能团以多糖为主,其次为脂肪碳和芳香碳,各官能团的丰度受紫云英种植和秸秆还田的影响。与其他处理相比,DSMV显著增加了水稻土中超大团聚体(>2 mm)和大团聚体(0.25～2 mm)的含量,并促进了两种团聚体内芳香碳等惰性碳的积累。因此,DSMV更有利于土壤团聚体和有机质稳定性的提升,在实际农业生产中具有较大的应用潜力。     

粪臭素对胃蛋白酶部分理化性质的影响

采用紫外光谱法和荧光光谱法研究了粪臭素与胃蛋白酶的结合作用。观测到粪臭素使胃蛋白酶的紫外吸收峰增强,特征荧光峰淬灭。Stern-Volmer淬灭曲线显示,粪臭素对胃蛋白酶的荧光淬灭很可能是一个单一的静态淬灭过程。