Studies on algal cytochromes. III. Amino acid sequence of cytochrome c-553 from a brown alga, Petalonia fascia

The amino acid sequence of a photosynthetic cytochrome c-553 isolated from a brown alga, Petalonia fascia was determined by BrCN fragmentation and a solid phase Edman degradation. The cytochrome contains 85 amino acid residues, giving a molecular weight of 9,803. The complete amino acid sequence is as follows: Val-Asp-Ile-Asn-Asn-Gly-Glu-Ser-Val-Phe-Thr-Ala-Asn-Cys-Ser-Ala-Cys-His-Ala-Gly -Gly-Asn-Asn-Val-Ile-Met-Pro-Glu-Lys-Thr-Leu-Lys-Lys-Asp-Ala-Leu-Glu-Glu-Asn-Gl u-Met-Asn-Asn-Ile-Lys-Ser-Ile-Thr-Tyr-Gln-Val-Thr-Asn-Gly-Lys-Asn-Ala-Met-Pro-A la-Phe-Gly-Gly-Arg-Leu-Ser-Glu-Thr-Asp-Ile-Glu-Asp-Val-Ala-Asn-Phe-Val-Ile-Ser-Gln-Ser-Gln-Lys-Gly-Trp. The highest homology was found between the sequences of cytochromes c-553 of P. fascia and Alaria esculenta, the next between those of P. fascia and Porphyria tenera.     

Digalactosyldiacylglycerols Isolated from a Brown Alga as Effective Phagostimulants for a Young Abalone

Sinorhizobium fredii USDA191 is a Gram-negative bacterium capable of forming nitrogen-fixing nodules on soybean roots. The USDA191 idhA gene encoding myo-inositol dehydrogenase, an enzyme necessary for myo-inositol utilization, is known to be involved in competitive nodulation and nitrogen fixation. In Bacillus subtilis, myo-inositol dehydrogenase catalyzes the first step of the myo-inositol catabolic pathway. Recently iolE was identified as the gene encoding 2-keto-myo-inositol dehydratase, which catalyzes the second step in the pathway. Here we report the presence of 2-keto-myo-inositol dehydratase activity in free-living USDA191 cells cultured in a medium containing myo-inositol. An iolE ortholog was cloned from USDA191. USDA191 iolE was expressed in Escherichia coli as a His₆-tag fusion and purified to exhibit 2-keto-myo-inositol dehydratase activity. Inactivation of USDA191 iolE led to defective myo-inositol utilization. USDA191 iolE partially complemented a B. subtilis iolE deficient mutant. These results suggest that S. fredii USDA191 utilizes a myo-inositol catabolic pathway, analogous to that of B. subtilis, involving at least idhA and iolE.     

An Anti-plasmin Inhibitor,Eckol, Isolated from the Brown Alga Ecklonia kurome Okamura

The biological activities of eckol, a novel phlorotannin with a dibenzo-β-dioxine skeleton, were examined. Eckol inhibited the antiplasmin activity of a₂-plasmin inhibitor very efficiently (IC₅₀; 1.6 μg/ml) as well as those of α₂-macroglobulin and -antitrypsin. However, its inhibitory effect on the antithrombin III-heparin complex was very weak. Eckol also showed inhibitory activity on thrombin (IC₅₀; 12 μg/ml), but not on plasmin. Its inhibitory activity was reduced in whole human plasma, but at concentrations of above 200 μg/ml it enhanced urokinase-induced fibrinolysis in human plasma. Studies on the inhibitory spectra of several derivatives of eckol showed that the dibenzo-l,4-dioxane skeleton was necessary for inhibition of plasmin inhibitor. These observations suggest that eckol or its derivatives may be useful clinically for potentiating thrombolytic activity.     

Pigment Composition of Chlorophyll-Protein Complexes Isolated from the Green Alga Bryopsis maxima

SDS-solubilized thylakoid membranes of Bryopsis maxima showeda similar pattern to those of higher plants in SDS-poIyacrylamidegel electrophoresis. Absorption spectra and pigment compositionof both CP1 and CPa bands were similar to those of higher plantsand other algae. Five bands containing chlorophyll (Chl) b weredivided into three categories; a group of major light-harvestingChl a/b-protein complexes (LHCP 1, LHCP 2 and LHCP 3), a minorLHCP (LHCP 3') and a photosystem I complex (CP1a). LHCP 1, thehigh molecular form, showed the lowest Chl a/b ratio among theLHCPs, and contained only xanthophylls as carotenoids. LHCP2, LHCP 3 and LHCP 3' bands contained xanthophylls and carotene.Carotenoid composition of LHCP 3' was different from that ofthe major LHCPs. CP1a band contained a considerable amount ofsiphonaxanthin and siphonein. (Received May 24, 1985; Accepted December 13, 1985)     

Chlorophyll-Protein Complexes Associated with Photosystem I Isolated from the Green Alga, Bryopsis maxima

Six chlorophyll (Chl)-protein complexes associated with photosystemI (CPla), and the PS I reaction center complex (CPl) were isolatedfrom the thylakoid membranes of the green alga, Bryopsis maxima,by SDS-polyacrylamide gel electrophoresis. CPla had four polypeptides(22, 24, 25, 26 kDa) in addition to the 67 kDa polypeptide ofCPl. These complexes may thus possibly be a combination of CPland antenna complexes for PS I. Six CPla showed almost the sameoptical properties, with absorption maxima at 650 and 677 nmand contained carotene and a small amount of xanthophylls. TheChl a/b ratios of these CPla were about 2, while that of CPlwas 14. CPla showed a fluorescence emission maximum at 695 nm;its excitation spectrum had peaks at 438, 470 and 540 nm, correspondingto the absorption maxima of Chl a, Chl b, xanthophylls, respectively.An antenna complex free of CPl has been detected in some plantsbut was not found in the present alga. ¹Present address: Department of Botany, The University of Adelaide,Adelaide, S.A. 5001, Australia (Received April 17, 1986; Accepted June 26, 1986)     

Isolation and Nomenclature of Pigment-Protein Complexes from the Brown Alga (Undaria pinnatifida Harv.)

Eight kinds of pigment-protein complexes were resolved from the thylakoid membrane of the brown alga （Undaria pinnatifida Harv.) by using non-ionic detergent decanoyl-N-methylglucamide and PAGE technique. According to the apparent molecular weights, spectra characteristics, polypeptide compositions and referring to the higher plant spinach, eight pigment-protein complexes were named under Anderson′s terminology system as CPⅠa, CPⅠ, CPa, LHC1, LHC2, LHC3, LHC4, LHC5.     

褐藻裙带菜色素—蛋白质复合物的分离与命名

以非离子去污剂癸基－Ｎ－甲基葡萄糖胺为增溶剂,采用聚丙烯酰胺凝胶电泳技术从褐藻裙带菜（Ｕｎｄａｒｉａ ｐｉｎｎａｔｉｆｉｄａ Ｈａｒｖ．）的类囊体膜上分离到８种色素－蛋白质复合物。根据其表观分子量、光谱特性和多肽分析结果,并以高等植物菠菜（Ｓｐｉｎａｃｉａ ｏｌｅｒａｃｅａ Ｌ．）为对照,按照Ａｎｄｅｒｓｏｎ命名系统,８种色素－蛋白质复合物分别命名为ＣＰⅠ ａ、ＣＰⅠ、ＣＰａ、ＬＨＣ１、ＬＨＣ２、     

Purification and Properties of Glycogen Isolated from a Blue-Green Alga, Nostoc muscorum

Alpha granules were isolated from a blue-green alga, Nostoc muscorum, in large quantities and high purity by sucrose density gradient centrifugation. Sodium deoxycholate was used to eliminate membrane contamination. Isolated alpha granules from this species have average dimension of 31 nm in width and 65 nm in length. Each alpha granule consists of two equal parts. Attempts to dissociate the intact granule under mild conditions into relatively large subunits did not succeed. Analytical centrifugation of the alpha granules yields a sedimentation coefficient of 265S (S(20, w)). Chemical analysis reveals that alpha granules contain highly branched polyglucosyl units with short external chain lengths.     

Protoplast isolation and regeneration from the potential economic brown alga Petalonia fascia (Ectocarpales,Phaeophyceae)

Journal of Applied Phycology - Petalonia fascia is a widespread brown alga with economic potential due to its use as raw or dried powder, and in the biomedical field. Protoplasts...     

Scanning Electron Microscopic Studies of Candida albicans

A scanning electron microscopic study of selected morphological stages of Candida albicans is presented. Stages represented are budding yeast cells, mycelial-like forms, chlamydospores, germ tube formation, and an unusual rough cell type.     

Circannual Growth Rhythm in a Brown Alga,Pterygophora californica

A circannual rhythm was found in the kelp Pterygophora californica which forms a new blade with a free running period of 7 ? 8 months under constant conditions. Individual plants exposed to cycles of daylength with T = 12, 6, or 3 months performed 1, 2, or 4 growth cycles, respectively, in one calendar year showing the entrainment of the endogenous circannual rhythm. The annual growth cycle also followed a phase shift of the annual cycle of daylength (T = 12 months) by 3 or 6 months.     

植物游离细胞扫描电镜样品的制备法

介绍了植物游离细胞扫描电镜样品的制备方法步骤和注意事项.     

Electron Microscopic and Physico-Chemical Studies of DNA Complexes with Synthetic Oligopeptides: Binding Specificity and DNA Compact Structures

Abstract

Binding to DNA of two synthetic peptides, Val-Thr-Thr-Val-Val-NH-NH-Dns and Thr-Val- Thr-Lys-Val-Gly-Thr-Lsy-Val-Gly-Thr-Val-Val-NH-NH-Dns (where Dns is a residue of 5- dimethylaminonaphthalene-l-sulfonic acid), has been studied by circular dichroism, electron microscopy and fluorescence methods. It has been found that these two peptides can self- associate in aqueous solution as follows from the fact that concentration-dependent changes are observed in the UV absorbance and fluorescence spectra. The two peptides can bind to DNA both in self-associated and monomeric forms. The pentapeptide in the β-associated form binds more strongly to poly(dG) · poly(dC) than to poly[d(A-C)] · poly[d(G-T)] and poly(dA) · poly(dT) whereas the tridecapeptide exhibits an opposite order of preferences binding more strongly to poly[d(A-C)] · poly[d(G-T)] and poly(dA) · poly(dT) than to poly(dG) · poly(dC).

Binding is a cooperative process which is accompanied by the DNA compaction at peptide/DNA base pair ratios greater than l. At the initial stage of the compaction process, the coalescence of DNA segments covered by bound peptide molecules leads to the formation of DNA loops stabilized by the interaction between peptide molecules bound to different DNA segments. Further increase in the peptide/DNA ratio leads to the formation of rod-like structures each consisting of two or more double-stranded DNA segments. The final stage of the compaction process involves folding of fibrillar macromolecular complexes into a globular structure containing only one DNA molecule.     

Induction of Callus from the Marine Brown Alga Dictyosiphon foeniculaceus

A method for callus induction from an alga was established forthe first time. Callus tissues from the microthallus of themarine brown alga Dictyosiphon foeniculaceus were induced onASP 12-NTA medium of Provasoli (1963) supplemented with 3% mannitol,0.1% yeast extract and 1.5% agar. The addition of auxins andkinetin to the medium did not show any effect on the formationand growth of the callus. (Received November 24, 1981; Accepted March 30, 1982)     

Electron Microscopic Studies on the Outer Layers of Staphylococcus aureus Using a Lytic Enzyme from Flavobacterium

The structure of the outer layers (cell wall and membrane) of Staphylococcus aureus was studied by electron microscope using a bacteriolytic enzyme from Flavobacterium sp. called the L-11 enzyme. Comparative studies on the morphology of bacteria before and after treatment with this enzyme and cell wall and membrane fractions obtained from bacteria after the enzyme treatment led to the following conclusions. (1) The cell wall of S. aureus is composed of morphologically distinct two layers which are both susceptible to the L-11 enzyme. (2) Between the cell wall and membrane, there is an electron opaque region which could not be stained using any of the methods tested. (3) Before treatment of bacteria with the enzyme the cell membrane could not be seen clearly. However, after enzyme treatment the membrane was clearly seen. (4) The infolding of the inner layer of the cell wall, forming a structure like a mesosome, was liberated by extensive enzyme treatment.     

Scanning Electron Microscopic Study of Cytoskeleton in Isolated Generative Cells of Lily

Isolated generative cells of lily were extracted with Triton X-100, ammonium sulphate and RNase. The exposed contents were then viewed in the scanning electron microscope after critical point drying. The treatments revealed that in the cytoplasm of the generative cell there was a reticulate network of cytoskeleton. This reticulate network of cytoskeletal scaffold had two layers: (1) an outer layer (near the membrane) consisting of long and thick fibres that were tightly knitted together, and (2) an inner layer (near the nucleus) consisting of thin and short fibres that were loosely knitted together. Indirect evidence using immunofluorescence techniques for labelling microtubules and TRITC-phalloidin staining of actin microfilaments indicated that the cytoskeleton seen in the scanning electron microscope appeared likely to be a microtubule cytoskeleton rather than a microfilament cytoskeleton.