Thermodynamic study of heteroligand complex formation of copper(II) and nickel(II) nitrilotriacetates with amino acids in solution

10 different compounds, including natural and synthetic polypeptides, proteins, polysaccharides, amino acids, and steroid hormones, were assayed for their capacity to form complexes with peritoneal exudate cell RNA. Only molecules carrying negatively charged groups were able to do so. The formation of RNA-antigen complexes was unrelated to the immuno-potency of the "antigen," was not an enzyme-dependent reaction, did not require the synthesis of RNA following introduction of the antigen, did not seem to involve antigen-specific RNAs, was not specific for macrophages, since HeLa cells could be used as effectively, and occurred when purified RNA was mixed with antigen only in the presence of divalent cations. The complexes were very stable, once formed, but could be dissociated by exhaustive dialysis against buffers containing a chelating agent. The macrophage RNA-antigen complex therefore appears to be a chelate between anionic groups on the two components. Based on the total absence of a relationship between immunogenicity and the capacity to form such complexes, as well as the nonspecific nature of complex formation at every level examined, it appears unlikely that RNA-antigen complexes play a physiologically significant role in immune induction.

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Essential role of amino acids in αD–β4 loop of a Bacillus thuringiensis Cyt2Aa2 toxin in binding and complex formation on lipid membrane

Toxicon ◽

10.1016/j.toxicon.2013.08.053 ◽

2013 ◽

Vol 74 ◽

pp. 130-137 ◽

Cited By ~ 5

Author(s):

Kunat Suktham ◽

Wanwarang Pathaichindachote ◽

Boonhiang Promdonkoy ◽

Chartchai Krittanai

Keyword(s):

Amino Acids ◽

Bacillus Thuringiensis ◽

Complex Formation ◽

Essential Role ◽

Lipid Membrane

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Structural analysis of point mutations at theVaccinia virusA20/D4 interface

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x16011778 ◽

2016 ◽

Vol 72 (9) ◽

pp. 687-691 ◽

Cited By ~ 4

Author(s):

Céline Contesto-Richefeu ◽

Nicolas Tarbouriech ◽

Xavier Brazzolotto ◽

Wim P. Burmeister ◽

Christophe N. Peyrefitte ◽

...

Keyword(s):

Crystal Structure ◽

Amino Acids ◽

Structural Analysis ◽

Complex Formation ◽

Dna Polymerase ◽

Point Mutations ◽

Conformational Space ◽

Uracil Dna Glycosylase ◽

Dimerization Interface ◽

Solvation Parameters

TheVaccinia viruspolymerase holoenzyme is composed of three subunits: E9, the catalytic DNA polymerase subunit; D4, a uracil-DNA glycosylase; and A20, a protein with no known enzymatic activity. The D4/A20 heterodimer is the DNA polymerase cofactor, the function of which is essential for processive DNA synthesis. The recent crystal structure of D4 bound to the first 50 amino acids of A20 (D4/A201–50) revealed the importance of three residues, forming a cation–π interaction at the dimerization interface, for complex formation. These are Arg167 and Pro173 of D4 and Trp43 of A20. Here, the crystal structures of the three mutants D4-R167A/A201–50, D4-P173G/A201–50and D4/A201–50-W43A are presented. The D4/A20 interface of the three structures has been analysed for atomic solvation parameters and cation–π interactions. This study confirms previous biochemical data and also points out the importance for stability of the restrained conformational space of Pro173. Moreover, these new structures will be useful for the design and rational improvement of known molecules targeting the D4/A20 interface.

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Thermodynamic study on supramolecular complex formation of theophylline derivates with a synthetic receptor

Tetrahedron Letters ◽

10.1016/s0040-4039(03)01245-0 ◽

2003 ◽

Vol 44 (29) ◽

pp. 5515-5517 ◽

Cited By ~ 2

Author(s):

Jeroni Morey ◽

Pablo Ballester ◽

Miquel Angel Barceló ◽

Antoni Costa ◽

Pere M Deyà

Keyword(s):

Complex Formation ◽

Supramolecular Complex ◽

Thermodynamic Study ◽

Synthetic Receptor

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Sorption of α-amino-acids by copper montmorillonite

Clay Minerals ◽

10.1180/claymin.1967.007.2.04 ◽

1967 ◽

Vol 7 (2) ◽

pp. 167-176 ◽

Cited By ~ 13

Author(s):

W. Bodenheimer ◽

L. Heller

Keyword(s):

Amino Acids ◽

Amino Acid ◽

Complex Formation ◽

Glutamic Acid ◽

Acid Complex ◽

X Ray ◽

Ray Methods

AbstractSorption of an acidic, amphoteric, sulphur containing and basic α-amino-acid (glutamic acid, glycine, methionine and lysine) by copper montmorillonite was studied by chemical and X-ray methods. With glutamic acid complex formation occurs only in solution but increasing basicity of the aminoacid favours complex formation in the clay interlayers.

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