Three-center (bifurcated) hydrogen bonding in the crystal structures of amino acids

1984 ◽  
Vol 106 (19) ◽  
pp. 5546-5553 ◽  
Author(s):  
G. A. Jeffrey ◽  
J. Mitra
2002 ◽  
Vol 58 (6) ◽  
pp. 1051-1056 ◽  
Author(s):  
N. T. Saraswathi ◽  
M. Vijayan

The crystal structures of the complexes of malonic acid with DL- and L-arginine, which contain positively charged argininium ions and negatively charged semimalonate ions, further demonstrate the conformational flexibility of amino acids. A larger proportion of folded conformations than would be expected on the basis of steric consideration appears to occur in arginine, presumably because of the requirements of hydrogen bonding. The aggregation pattern in the DL-arginine complex bears varying degrees of resemblance to patterns observed in other similar structures. An antiparallel hydrogen-bonded dimeric arrangement of arginine, and to a lesser extent lysine, is a recurring motif. Similarities also exist among the structures in the interactions with this motif and its assembly into larger features of aggregation. However, the aggregation pattern observed in the L-arginine complex differs from any observed so far, which demonstrates that all the general patterns of amino-acid aggregation have not yet been elucidated. The two complexes represent cases where the reversal of the chirality of half the amino-acid molecules leads to a fundamentally different aggregation pattern.


2001 ◽  
Vol 57 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Jiwen Cai ◽  
Xiaopeng Hu ◽  
Xiaolong Feng ◽  
Liangnian Ji ◽  
Ivan Bernal

The crystal structures and absolute configurations of three cis-β1 and three cis-β2 isomers of [Co(trien)(L-aminoacidato)]2+, namely β1-Λ(SSS)(λλδ)/(λδδ)-[Co(trien)(L-isoleucinato)](ClO4)2, L-isoleucinato(triethylenetetramine)cobalt(III) diperchlorate (1), β1-Λ(SRS)(λδλ)-[Co(trien)(L-valinato)](ClO4)2, L-valinato(triethylenetetramine)cobalt(III) diperchlorate (2), β1-Δ(RSS)(δλδ)-[Co(trien)(L-pyroglutamato)]ClO4, L-pyroglutamato(triethylenetetramine)cobalt(III) perchlorate (3), β2-Δ(RRS)(δδλ)-[Co(trien)(L-isoleucinato)]I2·H2O, L-isoleucinato(triethylenetetramine)cobalt(III) diiodide monohydrate (4), β2-Δ(RRS)(δδλ)-[Co(trien)(L-isoleucinato)](ClO4)2·2H2O, L-isoleucinato(triethylenetetramine)cobalt(III) diperchlorate dihydrate (5), and β2-Λ(SSS)(δλλ)[Co(trien)(L-leucinato)](ClO4)2·2H2O, L-leucinato(triethylenetetramine)cobalt(III) diperchlorate dihydrate (6), have been determined. Both β1 and β2 isomers form inter-cation hydrogen-bonding interactions through double or triple hydrogen bonds which link the cations into helices. However, the motifs of the interactions are different in β1 and β2 isomers, resulting in different packing structures. A localized hydrophobic area is observed in the packing structure of (1), a unique feature amongst these six structures. This work describes the first synthesis of the β1 isomer by direct reaction between amino acids and cis-α-[Co(trien)Cl2]Cl in mildly basic solution.


2014 ◽  
Vol 70 (a1) ◽  
pp. C272-C272 ◽  
Author(s):  
Eugene Kapustin ◽  
Vasliy Minkov ◽  
Elena Boldyreva

It is well known that infinite head to tail chains built of zwitterions linked to each other by N-H...O hydrogen bonds are common structural motifs in crystals of amino acids. These chains coincide with directions of the smallest compressibility of a crystal structure on cooling and increasing pressure and can even remain after structural phase transitions. However one should take into account the dual nature of these chains. From the one hand zwitterions of amino acids are linked by N-H...O hydrogen bonds formed from the head, amino group, and the tail, carboxylate group. From the other hand besides hydrogen bonding there is electrostatic interactions which occur between positively charged amino group and negatively charged carboxylate group. Being guided by an idea to distinguish electrostatic contribution from the charge assisted N-H...O hydrogen bonds and to understand their role in the crystal structure distortion on increasing pressure, two crystal structures of N-methyl derivatives of the simplest amino acid glycine are considered as a case study. N-methylglycine or sarcosine has two donors for hydrogen bonding and so forms two infinite head to tail chains in the structure whereas N,N,N-trimethylglycine or betaine has no hydrogen bonds at all, but its zwitterions are lined up resembling head to tail chains. The effect of increasing hydrostatic pressure is different for two crystals. The structure of betaine compresses anisotropically, but sarcosine undergoes a phase transition accompanying crystal fragmentation and changes in N-H...O hydrogen bonds. The phase transition is kinetically controlled and strongly depends on the rate of variation of pressure. Of special interest is distortion of head to tail chains on increasing pressure comparing with those observed in polymorphic modifications of glycine.


2020 ◽  
Vol 7 (21) ◽  
pp. 4197-4221 ◽  
Author(s):  
Francisco Colmenero ◽  
Jakub Plášil ◽  
Jiří Sejkora

The structure, hydrogen bonding, X-ray diffraction pattern and mechanical properties of six important uranyl carbonate minerals, roubaultite, fontanite, sharpite, widenmannite, grimselite and čejkaite, are determined using first principles methods.


Author(s):  
Jean-Cyrille Hierso ◽  
Elisabeth Bouwman ◽  
Dianne D. Ellis ◽  
Mónica Pérez Cabero ◽  
Jan Reedijk ◽  
...  

2014 ◽  
Vol 70 (a1) ◽  
pp. C534-C534
Author(s):  
Nasreddine Ghouari ◽  
Nourreedine Benali-Cherif

The theme of this work is part of the study of intermolecular interactions that hold the crystal structures of hybrid compounds based sulphuric acid, nitric acid, Melamine, Diethylamine, L-(+) - glutamic acid, DL-2-amino butyric acid. The aim of this work is to enlarge our laboratory researches [1-3] and methods in synthesis of new hybrid compounds consisting in organic cation(s) and mineral anion(s). We have obtained single crystals of a few samples after several trials and we plan to synthesize and characterize these crystals by X-ray diffraction, FTIR and Raman. The crystals structures allow us to study the 3D network hydrogen bonding, electron density and collect several other informations useful in FTIR and Raman studies of these hybrid compounds.


2016 ◽  
Vol 113 (26) ◽  
pp. 7160-7165 ◽  
Author(s):  
Oliver J. Harrison ◽  
Julia Brasch ◽  
Gorka Lasso ◽  
Phinikoula S. Katsamba ◽  
Goran Ahlsen ◽  
...  

Desmosomes are intercellular adhesive junctions that impart strength to vertebrate tissues. Their dense, ordered intercellular attachments are formed by desmogleins (Dsgs) and desmocollins (Dscs), but the nature of trans-cellular interactions between these specialized cadherins is unclear. Here, using solution biophysics and coated-bead aggregation experiments, we demonstrate family-wise heterophilic specificity: All Dsgs form adhesive dimers with all Dscs, with affinities characteristic of each Dsg:Dsc pair. Crystal structures of ectodomains from Dsg2 and Dsg3 and from Dsc1 and Dsc2 show binding through a strand-swap mechanism similar to that of homophilic classical cadherins. However, conserved charged amino acids inhibit Dsg:Dsg and Dsc:Dsc interactions by same-charge repulsion and promote heterophilic Dsg:Dsc interactions through opposite-charge attraction. These findings show that Dsg:Dsc heterodimers represent the fundamental adhesive unit of desmosomes and provide a structural framework for understanding desmosome assembly.


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