Prasad, Sridhar G and Vijayan, M (1990) X-ray studies on crystalline complexes involving amino acids and peptides XIX. Effects of change in chirality in the complexes of succinic acid with dl- and l-arginine. In: International Journal of Peptide & Protein Research, 35 (4). pp. 357-364.
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Crystals of dl-arginine hemisuccinate dihydrate (I)(monoclinic; P21/c; a = 5.292, b = 16.296, c = 15.203 Å; α= 92.89°; Z = 4) and l-arginine hemisuccinate hemisuccinic acid monohydrate (II) (triclinic; P1; a = 5.099; b = 10.222, c = 14.626 Å; α= 77.31, β= 89.46, γ= 78.42°; Z = 2) were grown under identical conditions from aqueous solutions of the components in molar proportions. The structures were solved by direct methods and refined to R = 0.068 for 2585 observed reflections in the case of (I) and R = 0.036 for 2154 observed reflections in the case of (11). Two of the three crystallographically independent arginine molecules in the complexes have conformations different from those observed so far in the crystal structures containing arginine. The succinic acid molecules and the succinate ions in the structures are centrosymmetric and planar. The crystal structure of (II) is highly pseudosymmetric. Arginine-succinate interactions in both the complexes involve specific guanidyl-carboxylate interactions. The basic elements of aggregation in both the structures are ribbons made up of alternating arginine dimers and succinate ions. However, the ribbons pack in different ways in the two structures. (II) presents an interesting case in which two ionisation states of the same molecule coexist in a crystal. The two complexes provide a good example of the effect of change in chirality on stoichiometry, conformation, aggregation, and ionisation state in the solid state.
Item Type: | Journal Article |
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Publication: | International Journal of Peptide & Protein Research |
Publisher: | John Wiley & Sons |
Additional Information: | Copyright of this article belongs to John Wiley & Sons. |
Keywords: | * amino acid aggregation; amino acid conformation;amino acid-succinic acid interactions;chemical evolution;effect of chirality;pseudosymmetry |
Department/Centre: | Division of Biological Sciences > Molecular Biophysics Unit |
Date Deposited: | 28 Dec 2010 06:50 |
Last Modified: | 28 Dec 2010 06:50 |
URI: | http://eprints.iisc.ac.in/id/eprint/34614 |
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