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
  • 1
    Electronic Resource
    Electronic Resource
    Crystallization of cytochrome b562 from Erwinia chrysanthemi (1997)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 53 (1997), S. 197-199 
    Details
    ISSN: 1399-0047
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: Cytochrome b562 from Erwinia chrysanthemi has been crystallized using the hanging-drop vapour-diffusion method with ammonium sulfate as the precipitant. X-ray precession photographs show that the crystals formed belong to either of the enantiomorphic space groups P41212 or P43212 with the cell parameters a = b = 98.6 and c = 62.7 Å. Estimation of the crystal density and consideration of the possible values for Vm indicate that there is either a dimer or trimer in the asymmetric unit. Experiments using the synchrotron radiation source at the CCLRC Daresbury Laboratory have shown that the crystals diffract to at least 2.7 Å resolution. An analysis of the N-terminal sequence indicates that this cytochrome shows limited homology to the cytochrome b562 from E. coli. Determination of the structure will therefore allow analysis of the relationship between these two proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0907444996011201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Necessity for weighting in Hamilton's R-factor ratio test (1970)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 26 (1970), S. 162-162 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: It is shown that there are theoretical grounds for believing that ratios of unweighted R-factors will be more variable than ratios of properly weighted least-squares minimization functions. An experimental confirmation of this is reported. It is recommended that apparently significantly large unweighted R-factor ratios should be checked with proper weighting.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0567739470000293
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    An application of the molecular replacement technique in direct space to a known protein structure (1975)
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 31 (1975), S. 499-506 
    Details
    ISSN: 1600-5724
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The molecular replacement technique in real space (successive cycles of electron density calculations, averaging among non-crystallographically equivalent subunits, and structure factor calculations based upon the improved averaged density) was applied to glyceraldehyde-3-phosphate dehydrogenase. It was shown possible (i) to extend the phases from a known 6.0 Å single isomorphous replacement set to at least 4.9 Å resolution; (ii) to determine a reasonable structure at low resolution given the molecular envelope and non-crystallographic symmetry; and (iii) to use the resulting low-resolution phases in the determination of heavy-atom sites. The application of such procedures to the determination of virus structures and heavy-atom derivative sites is discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0567739475001076
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Structure of Lactate Dehydrogenase at 2.8 Å Resolution (1970)
    [s.l.] : Nature Publishing Group
    Nature 227 (1970), S. 1098-1103 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Electron density distributions for the M4 isoenzyme of LDH reveal details of the conformation of the subunit, boundaries between the subunits, and features relevant to the binding of coenzyme and ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/2271098a0
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Intensity determination by profile-fitting applied to precession photographs (1974)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 7 (1974), S. 555-564 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A profile-fitting algorithm has been applied to the determination of X-ray diffraction intensities from precession photographs. It is assumed that each reflection on the film has the same profile or scaled intensity distribution, over a two-dimensional array of points about its center. The integrated intensity of a reflection is that scale factor which gives the best fit between a scaled model profile and the optical density measurements of the reflection. The systematic error in the calculated intensity was evaluated from the discrepancy between the model and observed profiles and was about 2% for strong reflections (about 1.5 OD units). Profile fitting reduced the likely random error in the intensity, produced by errors in optical density measurements, to half the value given by conventional integration. This gain is especially significant for weak reflections which form the bulk of protein data sets. A comparison between film data processed by this method and diffractometer data for the protein lactate dehydrogenase, (34000 Dalton in asymmetric unit), showed that film data agreed with diffractometer data as well as diffractometer data sets agreed among themselves. Film data for glyceraldehyde-3-phosphate dehydrogenase (144000 Dalton in asymmetric unit) had a reliability index of 6% and significant Bijvoet differences were measured for mercury derivatives of the protein. Methods for the correction for non-linear effects in film data are evaluated for model data. It is shown that these corrections give significant improvement only when the data satisfy two conditions: they extend over a wide range of optical densities (at least 20D units) and they are reliable (better than 4% reliability index). Under these conditions an extended version of the Hamilton, Rollett and Sparks scaling algorithm performs better than the other methods considered.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889874010430
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Dramatic increase in ferritin crystal lifetime with monochromatic synchrotron X-radiation tuned to a wavelength above the iron K absorption edge (1989)
    Copenhagen : International Union of Crystallography (IUCr)
    Applied crystallography online 22 (1989), S. 284-286 
    Details
    ISSN: 1600-5767
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Geosciences , Physics
    Notes: A dramatic increase in the lifetime of ferritin crystals during single-crystal X-ray diffraction data collection has been observed in experiments with monochromatic synchrotron X-radiation tuned to a wavelength slightly above the iron K absorption edge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0021889889000518
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    On versions of a procedure for scaling X-ray photographs (1968)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 24 (1968), S. 293-294 
    Details
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0567740868002190
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Electron impact and chemical ionization mass spectrometry of steroidal spirolactones (1978)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1978), S. 524-530 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron impact and chemical ionization mass spectra are reported for several steroidal spirolactones and their TMS ethers. The electron impact spectra were characterized generally by low abundance molecular ions and large numbers of fragment ions. Methane chemical ionization spectra exhibited high intensity [M+H]+ and/or [M+H—H2O]+ or [M+H—TMSOH]+ ions with few other fragment ions. Ammonia chemical ionization spectra had intense [M+H]+ and/or [M+NH4]+ ions with a few fragment ions generally formed by loss of H2O or TMSOH from these parent ions. Ammonia chemical ionization gave intense parent ions even for polyhydroxy compounds and their TMS ethers in contrast to methane chemical ionization. The results of this study suggest that a combination of electron impact with ammonia chemical ionization mass spectrometry would offer the best techniques for detection and identification of these compounds in biological fluids.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200050904
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    A ‘carrier effect’ observed in assays for antidiarrhoeal drug compounds (1978)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 5 (1978), S. 423-424 
    Details
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A carrier effect has been shown to exist in a stable isotope dilution assay for diphenoxylate. When a tetradeuterated analogue is used as a carrier and internal standard a sevenfold increase in sensitivity is observed for the unlabelled compound. Examination of a related pharmacologically active compound (SC-27166) showed a much smaller effect.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200050610
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Practical considerations in the use of stable isotope labelled compounds as tracers in clinical studies (1989)
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 18 (1989), S. 321-327 
    Details
    ISSN: 0887-6134
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Increasingly widespread usage of stable isotope tracers to aid clinical diagnosis and support basic research has stemmed from both advances in mass spectrometry and the availability of competitively priced labelled compounds. Stable isotopes have been used generally to investigate normal and abnormal metabolic pathways, to estimate energy expenditure and body composition and to quantitate substrate flux and oxidation rates. Despite the fact that the underlying principles relating to the use of stable isotopes for in vivo studies are straightforward, careful consideration must be given to all aspects of human studies. This review highlights some of these, including choice of label and tracer molecule, mode of tracer administration and sampling site, analytical instrumentation, interpretation of data and ethical constraints.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bms.1200180507
    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...