低温锻炼对小麦类囊体膜脂膜蛋白的影响

比较两种不同抗寒性小麦品种在低温锻炼前后类囊体膜脂及其脂肪酸成分、光系统Ⅱ捕光叶绿素ａ／ｂ 蛋白复合体（ＬＨＣⅡ）及类囊体吸收光谱,低温荧光发射光谱,发现经低温锻炼后：（１）抗寒与不抗寒品种小麦类囊体磷脂酰甘油（ＰＧ）的反式十六碳－烯酸含量均明显降低;抗寒品种小麦的单半乳糖基甘油二酯（ＭＧＤＧ）／双半乳糖基甘油二酯（ＤＧＤＧ）比值明显降低,而不抗寒品种变化不明显。（２）抗寒品种小麦类脂／叶绿素比值明显增高。（３）两品种小麦类囊体膜ＬＨＣⅡ寡聚体含量均降低,而单体含量均增加。（４）两品种小麦类囊体膜吸收四阶导数光谱Ａ６８３／Ａ６５２比值均升高。（５）不抗寒品种小麦低温荧光发射光谱Ｆ６８５／Ｆ７３８比值上升,而抗寒品种没有变化。我们认为,在低温锻炼过程中膜流动性增大可能是植物抗寒性增强的重要原因,此外,ＭＧＤＧ 含量降低对低温下膜双层的稳定性可能起重要作用     

大麦突变种Chlorina-f 2类囊体膜的叶绿素蛋白复合体

当突变种大麦Chlorina-f 2的类囊体膜在SDS/叶绿素的重量比为10:1,叶绿素的浓度为0.5mg/ml的条件下增溶,并在SDS-聚丙烯酰胺凝胶电泳中进行分离时,共出现4条含叶绿素的带。按电泳迁移率的增加,这些带分别是CP Ⅰ,CPa 1,CPa 2和FC。光谱测定表明CP Ⅰ为混有少量光系统Ⅱ??成分的光系统Ⅰ反应中心复合体,CPa 2为光系统Ⅱ反应中心复合体,CPa 2为光系统Ⅱ内周天线复合体。属于光系统Ⅰ的CP Ⅰ的叶绿素含量占总叶绿素的45.6%,而属于光系统Ⅱ的CPa Ⅰ和CPa 2的叶绿素之和则占总叶绿素的43.2%。可见在缺b大麦中,两个都失缺其外周天线的光系统的叶绿素含量是基本相等的。这和光合作用中两个光反应相互串联的理论是完全一致的。     

分离纯化后的烟草叶片液泡的显微观察

将分离纯化后的烟草叶片注佻 分别置于光镜和电镜下观察得到原生质体,原生质体释放液泡的过程,纯化后液泡的相应照片,结果说明我们选用的方法能得到完整的原生质体和液泡,且中央液泡是成熟植物细胞中体积最大的细胞器。     

STUDIES ON ISOLATED MEMBRANES OF AZUROPHIL AND SPECIFIC GRANULES FROM RABBIT POLYMORPHONUCLEAR LEUKOCYTES

Membranes were prepared from rabbit polymorphonuclear leukocyte azurophil and specific granules separated by zonal differential centrifugation. The two types of granule membranes were quite similar in ultrastructural appearance, but they showed distinct differences in cholesterol-phospholipid ratios and in protein components demonstrable in polyacrylamide gels.     

从超声波破碎的蓝藻类囊体膜中分离的叶绿素蛋白复合物

当蓝藻的类囊体膜用超声波进行破碎,并在4℃下用聚丙烯酰胺凝胶电泳进行分离,有6条叶绿素带被分离出来,它们分别是 CPIa,CPIb,CP1,CPa1 CPa2,FC。CP1 在红区和蓝区的吸收峰分别位于674和435 nm 处。在液氮甲该组分在725和680 nm 处有两个荧光发射带。CPa1和 CPa2的吸收光谱相似,其红峰和蓝峰的位置分别位于667和431.5nm 处。它们在77 K 的荧光发射峰都位于684 nm 处。用超声破碎法分离的叶绿素蛋白复合物的光谱特性,除 CPa1和 CPa2在红峰和蓝峰的吸收位置蓝移了3—5 nm 之外,其余与用 SDS 增溶法分离的相应复合物相似。属于光系统Ⅰ的 CPIa-CPI 的叶绿素含量占总叶绿素的40.93%,而属于光系统Ⅱ的 CPa1和 CPa2的叶绿素则占总叶绿素的38.78%,二者之差仅有2.15%。     

LIPIDS AND LIGHT-DEPENDENT SWELLING OF ISOLATED SPINACH CHLOROPLASTS

The light-dependent high-amplitude swelling of spinach chloroplastssuspended in 175 mM NaCl buffered with 50 mM Tris-HCl (pH 7.9)was investigated by a packed weight technique and by electronmicroscopy. Endogenous neutral and charged lipids were releasedby the thylakoid membrane to about the same extent during chloroplastincubation in both the light and the dark. The addition of laurate,oleate, stearate, lecithin and lysolecithin increased chloroplastswelling in the dark, but inhibited swelling in the light. Acetoneincreased chloroplast swelling at low concentrations and inhibitedat high concentrations in both the light and the dark. For 20%acetone, the grana stacks disappeared and a newly formed membranesystem appeared which was similar to a myelin structure. Therole of lipid components in the conformation of the membranestructure is discussed and a mechanism for lightinduced chloroplastswelling based on a hydrogen-sodium exchange is proposed. ¹ Present address: Department of Botanical Sciences, Universityof California, Los Angeles, California 90024.     

双氯雷公藤内酯四醇的分离与结构研究

从雷公藤（Ｔｒｉｐｔｅｒｙｇｉｕｍ ｗ ｉｌｆｏｒｄｉｉＨｏｏｋ．ｆ．）的叶中分离出１个新的含氯环氧二萜内酯化合物。据其理化数据和光谱分析,并结合分子图形学和分子力学计算,确定了它的化学结构,命名为双氯雷公藤内酯四醇（ｄｉｃｈｌｏｒｏｔｒｉｐｔｅｔｒａｏｌｉｄｅ）。     

FATTY ACID AND FATTY ALDEHYDE COMPOSITION OF GLIAL CELL LIPIDS ISOLATED FROM BOVINE WHITE MATTER

Abstract— Glial cells were isolated from bovine white matter by differential centrifugation. The fatty aldehyde and fatty acid compositions of ethanolamine glycerophosphatides (EGP), serine glycerophosphatides (SGP) and choline glycerophosphatides (CGP) were determined by gas-liquid chromatography. The fatty acid compositions of the sphingo-lipids including sphingomyelin, cerebroside and cerebroside sulphate, and of minor lipid components including cholesterol esters and triglycerides, were also determined by gas-liquid chromatography. The relative proportions correlated closely with the results obtained by O'B rien and S ampson (1965 b ) for adult human brain. The fatty aldehyde compositions of the glycerophosphatides were more closely related to the corresponding fatty acid compositions of the plasma membrane than of the mitochondria. Long-chain fatty acids (19–26 carbon atoms) were detected in sphingomyelin, cerebroside and cerebroside sulphate; this indicates that chain-elongation beyond C₁₈ occurs in the glial cells.     

FINE STRUCTURE OF CELLS ISOLATED FROM ADULT MOUSE LIVER

Suspensions of isolated cells in various media were prepared from mouse liver which had been perfused via the portal vein with a buffered medium containing 0.40 M sucrose, and the cells were fixed with osmium tetroxide. Their fine structure was compared with that of cells from perfused and unperfused intact liver. Perfusion brought about some separation of the cells with little or no damage to cell membranes. When cells were dispersed in 0.40 M sucrose medium the plasma membranes partially broke down, and this disintegration was increased by transfer of the cells to media of lower osmolarity. This is presumed to account for the loss of permeability barriers which occurs in isolated liver cells. The mitochondria in cells of perfused liver and in isolated cells remained elongated, but the layers of many mitochondrial cristae became separated by clear spaces. When cells were transferred to a medium containing 0.20 M sucrose, the mitochondria swelled and became spherical, often with displacement of the swollen cristae to the periphery. In a medium containing 0.06 M sucrose and 0.08 M potassium chloride the outer chamber of many mitochondria became swollen with displacement of the mitochondrial body to one side to give a crescent-shaped appearance. These changes in mitochondrial morphology are discussed in relation to the metabolic activity of isolated liver cells.     

ANALYTICAL STUDY OF MICROSOMES AND ISOLATED SUBCELLULAR MEMBRANES FROM RAT LIVER : I. Biochemical Methods

The series introduced by this paper reports the results of a detailed analysis of the microsomal fraction from rat liver by density gradient centrifugation. The biochemical methods used throughout this work for the determination of monoamine oxidase, NADH cytochrome c reductase, NADPH cytochrome c reductase, cytochrome oxidase, catalase, aminopyrine demethylase, cytochromes b₅ and P 450, glucuronyltransferase, galactosyltransferase, esterase, alkaline and acid phosphatases, 5'-nucleotidase, glucose 6-phosphatase, alkaline phosphodiesterase I, N-acetyl-β-glucosaminidase, β-glucuronidase, nucleoside diphosphatase, aldolase, fumarase, glutamine synthetase, protein, phospholipid, cholesterol, and RNA are described and justified when necessary.     

SOME IMMUNOCHEMICAL CHARACTERISTICS OF W1 AND W2 WOLFGRAM PROTEINS ISOLATED FROM RAT BRAIN MYELIN

Starting from a chloroform-methanol (2: 1 v/v) insoluble pellet of rat brain myelin, two pure proteins W1 and W2 were isolated by sodium dodecylsulphate preparative polyacrylamide gel electrophoresis. Their amino acid composition was compared. Antibodies against these proteins were prepared in rabbits. It was found that the two antigens have common antigenic similarities. The presence of one precipitin line of identity when myelin or isolated W1 and W2 from different animals were tested, led to the conclusion that there was no species specificity. The importance of the availability of such antisera is discussed.     

STRUCTURE AND COMPOSITION OF OOCYSTIS POLYMORPHA CELL WALLS ISOLATED FROM THE CULTURE MEDIUM1

Oocystis polymorpha and possibly other algae which shed their parent-cell walls during reproduction appear to be suitable organisms for cell wall research in that the cell walls can be readily collected from the culture medium. Electron micrographs of sectioned isolated cell walls, of the parent-cell walls, and of the daughter cells appear to be identical, suggesting that the isolated cell walls are representative of those of the intact cell. Chemically, the cell walls of Oocystis polymorpha resemble the cell walls of Cyanidium and the chemically resistant cuticle fraction of Cladophora and Porphyra in their high nitrogen and low sugar and lipid contents. Pink carotenoids are the major lipid components of the cell walls.     

光周期对光敏核不育水稻叶绿体类囊体膜超分子结构的影响

通过冰冻撕裂叶绿体类囊体膜电镜术的研究,在超分子水平上揭示出长日照（ＬＤ）与短日照（ＳＤ）对突变型光敏核雄性不育水稻农垦５８Ｓ及其野生型农垦５８ 倒二叶叶绿体类囊体膜的形成有不同的影响。农垦５８－ＳＤ 和农垦５８－ＬＤ差别不明显;而农垦５８Ｓ－ＳＤ和农垦５８Ｓ－ＬＤ之间出现较明显的差异：（１）农垦５８Ｓ－ＳＤ 叶绿体类囊体膜的垛叠和非垛叠膜区的４ 个冰冻撕裂膜小面呈现的功能蛋白粒的密度、大小及构象分布与其对照农垦５８－ＳＤ 和农垦５８－ＬＤ 类似,均属正常的超分子结构类型。（２）农垦５８Ｓ－ＳＤ叶绿体垛叠类囊体膜区的外质撕裂面（ＥＦｓ）功能蛋白粒的密度比５８Ｓ－ＬＤ的大,且在有的垛叠膜区呈现出类晶格状的规则排列。（３）农垦５８Ｓ－ＬＤ 叶绿体非垛叠膜区的原生质撕裂面（ＰＦｕ）和外质撕裂面（ＥＦｕ）出现频率较低,往往在基粒的边缘膜或末端中能找到,且分布于膜上的功能蛋白粒的密度较小。有的叶绿体ＥＦｕ、ＰＦｕ、ＥＦｓ和垛叠膜区原生质撕裂面（ＰＦｓ）功能蛋白粒极少或丧失,表明类囊体膜受到严重损伤     

中国和日本分离的几株流行性出血热病毒的抗原性比较

采用间接免疫荧光法(IFA)和ELISA法比较了几株中国和日本流行性出血热病毒(EHFV)的抗原性,IFA法不能区分大鼠属和姬鼠属来源的病毒,ELISA竞争试验表明,大鼠型病毒(R22、SR-11和TR-352株)与姬鼠型病毒(A 9株)存在弱单向交叉反应,交叉ELISA证实,A 9株与R22株、SR-11株和TR-352株均有较显著的抗原性差异,但R22,SR-11和TR-352株彼此间抗原性相近,本文讨论了有关EHFV抗原性比较中的一些问题。     

铜对类囊体膜叶绿素-蛋白质复合物组成和光谱特性的影响

菠菜和青菜类囊体膜经SDS-PAGE*可分别分离出8条和7条含叶绿素的区带。经Cu螯合剂处理后发现菠菜CPIa、青菜CPI_a、LHCP_2带缺失,菠菜CPIa_1 LHCP_2和青菜CPI减少,两者的LHCP_3明显增加。外源Cu(5mmol/L CuCl_2)可使菠菜CPa_1带缺失。青菜CP_a带缺失,并且使菠菜CPI带的吸收峰由678nm移到672nm,在652nm处有一微弱小肩,并且出现679nm荧光发射峰,表现出LHC-Ⅱ的某些光谱特性。同时使菠菜和青菜的LHCP_1和LHCP_2的吸收峰均由672nm分别移到668nm和669nm,并且使LHCP_2在724nm处产生较强的荧光发射,接近于LHC-Ⅰ的某些光谱特性。由此初步认为,铜可能通过变构作用来调节两个光系统间从作用中心到捕光色素蛋白复合物,以及二者捕光色素蛋白复合物本身之间的能量转移。