ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
  • valinomycin analogue  (2)
  • 1
    ISSN: 0006-3525
    Keywords: x-ray crystallography ; ionophore ; valinomycin analogue ; crystal and molecular structure ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The crystal and molecular structure of the valinomycin analogue, cyclo [(D-Val-L-Lac-L-Ala-D-Hyi)2 (D-Val-L-Lac-L-Val-D-Hyi)] has been solved by x-ray direct methods using the “Shake and Bake” procedure. The crystals, grown from a mixture of octane/CH2Cl2, belong to space group P21 (Z = 4 ) with cell parameters a = 10.29, b = 32.08, c = 18.73 Å β = 97.05°, and contain two molecules per asymmetric unit. After anisotropic refinement the standard reliability factor was R1 = 0.058. The conformations of both independent molecules is similar to that observed for isoleucinomycin, cyclo [-(D-Ile-L-Lac-L-Ile-D-Hyi)3] [V. Z. Pletnev et al. (1980) Biopolymers, Vol. 19, pp. 1517-1534]. The structure has an asymmetric conformation stabilized by six intramolecular H bonds, five bonds being of the 4 → 1 type and one bond being of the 5 → 1 type. One water molecule is caged in the internal cavity of each cyclodepsipeptide. This conformation could represent an intermediate state between free and complexed forms of valinomycin. © 1997 John Wiley & Sons, Inc. Biopoly 42: 651-658, 1997
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0006-3525
    Keywords: valinomycin analogue ; ionophore ; x-ray direct methods ; structure and function ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The conformation and intermolecular association of [D-Hyi2, L-Hyi4]meso-valinomycin {cyclo[-D-Val-D-Hyi-L-Val-L-Hyi- (D-Val-L-Hyi-L-Val-D-Hyi)2-], C60H102N6O18} in a crystal form obtained from ethanol solution has been determined by x-ray crystallography. Two depsipeptides and one ethanol molecule per asymmetric unit crystallize in space group P21 (Z = 4); a - 14.579, b = 39.795, c = 13.928 Å, β = 116.90, R1 = 0.0757. The molecular conformation is very similar to that observed in the trigonal P32 crystal form obtained from acetone solution [V. Z. Pletnev et al. (1991) Biopolymers, Vol. 31, pp. 409-415]. Both independent molecules in the crystal adopt a similar distorted bracelet structure with a sterically inaccessible, partially formed, ion-binding center that is stabilized by six 4 → 1 type H bonds. The observed conformation accounts for the inability of the molecule to complex ions. Close examination of the three crystallographically independent molecules reveals that differences in the backbone conformation associated with solvent interaction are significantly larger than those associated with hydrophobic van der Waals interactions of crystal packing.© 1997 John Wiley & Sons, Inc. Biopoly 42: 645-650, 1997
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...