Mechanism of non-enzymic transamination reaction between histidine and α-oxoglutaric acid

Non-enzymic transamination reactions at 85° between various amino acids and α-oxoglutaric acid are catalysed by metal ions, e.g. Al3+, Fe2+, Cu2+ and Fe3+. The reaction is optimum at pH4·0. Of the 14 amino acids studied histidine is the most active. In the presence of Al3+ histidine transaminates with α-oxoglutaric acid, forming glutamic acid and Al3+–imidazolylpyruvic acid complex as the end products. However, in the presence of Fe2+ or Cu2+ the products are glutamic acid and a 1:2 metal ion–imidazolylpyruvic acid chelate. The greater effectiveness of histidine in these reactions is attributed to the presence of the tertiary imidazole nitrogen atom, which is involved in the formation of stable sparingly soluble metal ion–imidazolylpyruvic acid complexes or chelates as end products of these reactions. Of the metal ions studied only Al3+, Fe2+, Fe3+ and Cu2+ are effective catalysts for the transamination reactions, and EDTA addition completely inhibits the catalytic effect of the Al3+. Spectrophotometric evidence is presented to demonstrate the presence of metal ion complexes of Schiff bases of histidine as intermediates in the transamination reactions. These results may contribute to understanding the role of histidine in enzyme catalysis.

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Why do zeolites induce an unprecedented electronic state on exchanged metal ions?

Physical Chemistry Chemical Physics ◽

10.1039/c7cp02669b ◽

2017 ◽

Vol 19 (36) ◽

pp. 25105-25114 ◽

Cited By ~ 5

Author(s):

Akira Oda ◽

Takahiro Ohkubo ◽

Takashi Yumura ◽

Hisayoshi Kobayashi ◽

Yasushige Kuroda

Keyword(s):

Metal Ions ◽

Electronic State ◽

Base Metal ◽

Metal Ion ◽

High Efficiency ◽

Lewis Base ◽

Mfi Zeolite ◽

Adsorption Processes ◽

Exact Position

Understanding the exact position and the detailed role of the Al array in zeolites is essential for elucidating the origin of unique properties and for designing zeolite materials with high efficiency in catalytic and adsorption processes. In this work, we advanced pivotal roles of Lewis base–metal ion bifunctionality caused by Al atoms arrayed circumferentially in the MFI-zeolite pores.

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Coordination chemistry of glutathione.

Acta Biochimica Polonica ◽

10.18388/abp.1999_4129 ◽

1999 ◽

Vol 46 (3) ◽

pp. 567-580 ◽

Cited By ~ 64

Author(s):

A Krezel ◽

W Bal

Keyword(s):

Glutamic Acid ◽

Metal Ions ◽

Metal Ion ◽

Reduced Glutathione ◽

Transition Metal Ions ◽

Oxidized Glutathione ◽

Binding Modes ◽

Glutamic Acid Residue ◽

Reduced And Oxidized Glutathione ◽

Soft Metal

The metal ion coordination abilities of reduced and oxidized glutathione are reviewed. Reduced glutathione (GSH) is a very versatile ligand, forming stable complexes with both hard and soft metal ions. Several general binding modes of GSH are described. Soft metal ions coordinate exclusively or primarily through thiol sulfur. Hard ones prefer the amino acid-like moiety of the glutamic acid residue. Several transition metal ions can additionally coordinate to the peptide nitrogen of the gamma-Glu-Cys bond. Oxidized glutathione lacks the thiol function. Nevertheless, it proves to be a surprisingly efficient ligand for a range of metal ions, coordinating them primarily through the donors of the glutamic acid residue.

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The Role of Metals in the Reaction Catalyzed by Metal-Ion-Independent Bacillary RNase

Bioinorganic Chemistry and Applications ◽

10.1155/2016/4121960 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Yulia Sokurenko ◽

Vera Ulyanova ◽

Pavel Zelenikhin ◽

Alexey Kolpakov ◽

Dmitriy Blokhin ◽

...

Keyword(s):

Metal Ions ◽

Rna Structure ◽

Metal Ion ◽

Extracellular Enzymes ◽

Bacillus Pumilus ◽

Transition Metal Ions ◽

The Body ◽

Intestinal Microbiome ◽

Phosphodiester Bond

Extracellular enzymes of intestinal microbiota are the key agents that affect functional activity of the body as they directly interact with epithelial and immune cells. Several species of theBacillusgenus, likeBacillus pumilus, a common producer of extracellular RNase binase, can populate the intestinal microbiome as a colonizing organism. Without involving metal ions as cofactors, binase depolymerizes RNA by cleaving the 3′,5′-phosphodiester bond and generates 2′,3′-cyclic guanosine phosphates in the first stage of a catalytic reaction. Maintained in the reaction mixture for more than one hour, such messengers can affect the human intestinal microflora and the human body. In the present study, we found that the rate of 2′,3′-cGMP was growing in the presence of transition metals that stabilized the RNA structure. At the same time, transition metal ions only marginally reduced the amount of 2′,3′-cGMP, blocking binase recognition sites of guanine at N7 of nucleophilic purine bases.

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The Role of Alteration of Glutamic Acid and Gaba in Learning and Memory Impairment of Rats Induced by Aluminum

European Journal of Inflammation ◽

10.1177/1721727x0500300207 ◽

2005 ◽

Vol 3 (2) ◽

pp. 97-101

Author(s):

Q. Niu ◽

P. Niu ◽

Q. Zhang ◽

L. Wang ◽

S. He ◽

...

Keyword(s):

Amino Acids ◽

Cerebral Cortex ◽

Glutamic Acid ◽

Learning And Memory ◽

Memory Impairment ◽

High Performance ◽

Gamma Aminobutyric Acid ◽

Aluminum Exposure ◽

Step Down

Aluminum exposure has been reported to be related to learning and memory impairment. This study examines the role of aluminum in alterating amino acids of the cerebral cortex of rats. The Step-down type tests were performed to investigate the alteration of learning and memory of rats induced by aluminum. The amino acids in the cerebral cortex were detected by high performance liquid chromatography (HLPC). Results show that the amounts of aluminum in the cerebral cortex increased by 5.0mgAl3+/(Kg·BW) group and 10.0mg Al3+/(Kg·BW) group. In the Step-down type test, the EN1 increased significantly in the Al3+ 10.0mg/(Kg·BW) group. The latency shortened obviously and the EN2 increased significantly in the 10.0mg Al3+/(Kg·BW) group. The content of Glu (Glutamic acid) increased but the content of GABA (gamma-aminobutyric acid) decreased significantly in the 10.0mg Al3+/(Kg·BW) group. This present study shows evidence that the disorder of amino acid neurotransmitters system plays an important role in the impairment of learning and memory of rats induced by aluminum.

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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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Elucidating the role of metal ions in carbonic anhydrase catalysis

Nature Communications ◽

10.1038/s41467-020-18425-5 ◽

2020 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Jin Kyun Kim ◽

Cheol Lee ◽

Seon Woo Lim ◽

Aniruddha Adhikari ◽

Jacob T. Andring ◽

...

Keyword(s):

Carbonic Anhydrase ◽

Metal Ions ◽

Metal Ion ◽

Catalytic Mechanism ◽

Chemical Properties ◽

Water Network ◽

Native Metal ◽

Trigonal Bipyramidal ◽

Electrostatic Effect

Abstract Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 Å) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties.

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