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
  • Analytical Chemistry and Spectroscopy  (3)
  • liposomes  (2)
  • 1985-1989  (5)
  • 1920-1924
  • 1
    Electronic Resource
    Electronic Resource
    Local dielectric properties around polar region of lipid bilayer membranes (1985)
    Springer
    The journal of membrane biology 85 (1985), S. 225-231 
    Details
    ISSN: 1432-1424
    Keywords: dielectric constant ; fluorescence study ; liposomes ; calcium effect ; phase transition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Local dielectric constant was evaluated from the Stokes shifts of fluorescence spectra ofl-α-dansylphosphatidylethanolamine (DPE) incorporated into liposomes made of synthetic phosphatidylcholine (dipalmitoyl or distearoyl) or bovine brain phosphatidylserine. The evaluation was established as follows. First, the Stokes shift of DPE was assured to follow Mataga-Lippert's equation and was a function of the dielectric constant and the refractive index in some standard organic solvents. Second, the change of the refractive index did not contribute much to the change in the Stokes shift. Third, the time resolved fluorescence depolarization of DPE in liposomes showed that the cone wobbling diffusion was rapid relative to the fluorescence lifetime and therefore that the dielectric relaxation did not affect the evaluation of the constant in the polar region of membranes. We then investigated the characteristics of the local dielectric constant in the polar region of the lipid bilayer and found that the dielectric constant varies between 4 and 34 depending upon calcium binding and also gel/liquid-crystal phase transition. Such large changes of the local dielectric constant were further correlated with the dynamic structure of lipid bilayer membranes measured by conventional fluorescence depolarization techniques. The large changes of dielectric constant around the polar region suggest that electrostatic interactions at this region can be altered 10-fold by such ionic or thermotropic factors and therefore that local dielectric properties can play crucial roles in membrane functions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01871517
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Phospholipase C and the physical states of polar head groups of lipids (1987)
    Springer
    The journal of membrane biology 96 (1987), S. 187-191 
    Details
    ISSN: 1432-1424
    Keywords: phospholipase C ; liposomes ; fluorescence study ; local dielectric property ; rotational freedom
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary Activity of phospholipase C fromClostridium perfringens on liposomes made fromsn-3-phosphatidylcholine, dimyristoyl (DMPC), dipalmitoyl (DPPC) or distearoyl (DSPC) was measured at various temperatures and was correlated with their gel/liquid-crystalline phase transitions (T c : 23, 41.5, 52°C for DMPC, DPPC, DSPC, respectively). In all cases, the activity of phospholipase C was high in the gel phases of the substrates and was almost zero in their liquid-crystalline phases. Fluorescence depolarization measurements of N-dansyl-sn-3-phosphatidylethanolamine (DPE) and 1,6-diphenyl-1,3,5-hexatriene (DPH) incorporated into the liposomes showed that both the head group and the alkyl chains of the lipids were immobilized in the gel phases but were highly mobile in the liquid-crystalline phase. These results indicate that the rotational mobility of lipids (both of the head groups and the alkyl chains) was not a major factor in the phospholipase C reaction. It is inferred that some electrostatic and/or hydrophobic interactions might play important roles in regulation of the phospholipase C activity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01869244
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Structural investigation of the antibiotic sporaviridin: 11 - Molecular secondary ion mass spectral studies on the constituent pentasaccharides viridopentaosesFor Part 10 see K.-I. Harada, I. Kimura, E. Takami and M. Suzuki, J. Antibiotics 37, 976 (1984). (1985)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 20 (1985), S. 582-588 
    Details
    ISSN: 0030-493X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular secondary ion mass spectra of three pentasaccharides, viridopentaoses A, B and C, using various matrices, are discussed. The appearance of the molecular ion species is dependent upon the relative proton affinities between the sample and the organic matrix material. However, the presence of sodium ion, rather than proton, also greatly influences the appearance of the molecular ion species. The glycosidic linkages are mainly cleaved between the glycosidic oxygen atom and the anomeric carbon atom to give informative sugar sequence ions. These fragmentations have been confirmed by the linked scanning technique (B/E).
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/oms.1210200910
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Isotropic Raman band shape and vibrational relaxation for molecules in the liquid state: A Critical study of some band shape functions (1985)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 16 (1985), S. 377-385 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A band shape function for the isotropic Raman scattering described in terms of the band width in the weak coupling limit and the relaxation time of the bath mode has been proposed by summing the results of Berne et al. [J. Chem. Phys. 45, 1086 (1966)], Wang [Mol. Phys. 33, 207 (1977)] and Knauss [Mol. Phys. 36, 413 (1978)]. The results of band analyses with this function have been compared with those obtained from other conventionally used band shape and correlation functions. The present function is preferable for precise interpretation of vibrational relaxation mechanisms, particularly for those cases where temperature and concentration dependence of the band parameters are involved.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250160606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Raman spectra of halogen-substituted methanes in the liquid state. 3For Part 2, see Ref. 2. - Temperature effects (1987)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 18 (1987), S. 47-52 
    Details
    ISSN: 0377-0486
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of temperature on the peak positions, the isotropic and reorientational band widths and the depolarization ratios of the Raman bands for the totally symmetric vibrations of CHCl3, CH2Cl2, CH2Br2, CH3Br, CH3I and CD3I has been measured in the liquid state. The isotropic band width for a C—X stretching vibration decreases with increasing temperature for molecule with only one C—X bond, whereas it increases for a molecule with two or three equivalent C—X bonds. The isotropic band width for the deformation vibrations decreases with increase in temperature. For all the bands, the depolarization ratios depend only slightly on temperature.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jrs.1250180109
    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...