ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Trehalose  (1)
  • nif gene expression  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Ultrastructural analysis of the rehydration of desiccatedNostoc commune HUN (cyanobacteria) with particular reference to the immunolabelling of NifH (1988)
    Springer
    Protoplasma 146 (1988), S. 72-80 
    Details
    ISSN: 1615-6102
    Keywords: Heterocysts ; Nitrogenase ; Fe protein ; nif gene expression ; Oxygen sensitivity ; Sheath material
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Vegetative cells and heterocysts of the filamentous desiccation-tolerant cyanobacteriumNostoc commune HUN retain their ultrastructural organisation and the integrity of their intra- and extracellular membranes after two years of desiccation and subsequent rehydration. Immunogold-labelling of thin sections demonstrated the presence of NifH (Fe protein of nitrogenase) in vegetative cells and heterocysts within five minutes of the rehydration of dried colonies. Immunogold label accumulated in discrete areas vegetative cells within 5 minutes of the rewetting of cells, and after 30 minutes a conspicuous association of NifH protein with heterocyst ribosomes was detected. After longer periods of rehydration, the deposition of gold particles became more random within both cell types but occurred with a greater frequency in heterocysts. Up to 24 hours after the rewetting of cells, two morphologically-distinct forms of heterocyst could be discerned. NifH protein was detected through Western blotting (subunit Mr=33,800) in protein extracts from samples ofNostoc commune, collected in different parts of the world and including some which had been desiccated for periods of up to 10 years. The results are discussed in relation to the sequential recovery of metabolic functions, particularly nitrogen fixation, which occurs upon the rehydration of cells after their prolonged storage in the air-dry state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01405915
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Biochemistry and structure of the glycan secreted by desiccation-tolerantNostoc commune (Cyanobacteria) (1994)
    Springer
    Protoplasma 182 (1994), S. 126-148 
    Details
    ISSN: 1615-6102
    Keywords: UV-absorbing pigments ; Protein secretion ; Capsule ; Glycoproteins ; Trehalose
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Filaments of the desiccation-tolerant cyanobacteriumNostoc commune are embedded within, and distributed throughout, a dense glycan sheath. Analysis of the glycan of field materials and of pure cultures ofN. commune DRH 1 through light and electron microscopy, immunogold labelling and staining with dyes, revealed changes in the pattern of differentiation in glycan micro-structure, as well as localized shifts in pH, upon rehydration of desiccated field material. A Ca/Si rich external (pellicular) layer of the glycan acts as a physical barrier to epiphytic bacteria on the surface ofN. commune colonies. A purified fraction (〉12 kDa) of an aqueous extract of the glycan from desiccated field material contained glucose, N-acetylglucosamine, glucosamine, mannose, and galactosamine with ratios of 3.1∶1.4∶1∶0.1∶0.06, respectively. Lipid soluble extracts ofN. commune contained trehalose and sucrose and the levels of both became undetectable following cell rehydration. Intracellular cyanobacterial trehalase was identified using immunoblotting and its synthesis was detected upon rehydration of desiccated field cultures. Elemental analysis of glycan extracts showed a flux in the concentrations of salts in the glycan matrix following rehydration of desiccated colonies. Water-stress proteins (Wsp; most abundant proteins in glycan), a water soluble UV-A/B-absorbing pigment, the lipid-soluble UV-protective pigment scytonemin (in both its oxidized and reduced forms), as well as two unidentified cyanobacterial glycoproteins (75 kDa and 110 kDa), were found within the glycan matrix. An unidentified 68 kDa protein, the second most abundant protein in aqueous extracts of the glycan, was isolated and its N-terminal sequence was determined as AFIFGTISPNNLSGTSGNSGIVGSA. Gene bank searches with this sequence identified significant homologies (35–45%) with various carbohydrate-modifying enzymes. The role of the glycan in the desiccation tolerance ofN. commune is discussed with respect to structure/function relationships.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01403474
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...