Histamine metal-binding

Marchelli used the copper(II) complex of histamine-functionalized P-cy-clodextrin for chiral recognition and separation of amino acids [27]. The best results were obtained for aromatic amino acids (Trp). Enantioselective sensing of amino acids by copper(II) complexes of phenylalanine-based fluorescent P-cyclodextrin has been recently published by the same author [28, 29]. The host containing a metal-binding site and a dansyl fluorophore was shown to form copper(II) complexes with fluorescence quenching. Addition of d- or L-amino acids induced a switch on of the fluorescence, which was enantioselective for Pro, Phe, and Trp. This effect was used for the determination of the optical purity of proline. 

Several mammalian natural agonists are metal-binding, notably thyroxine 11.14), norepinephrine (7.5), and histamine 7.6). Only mammalian mitochondria accumulate calcium. 

Several mammalian hormones are metal-binding, e.g. thyroxine (//.//), histamine (7.6), and noradrenaline (7.5). The accumulation of calcium by mitochondria (mammalian only) was discussed in Section 11.0. 

Hormone examples. The metal-binding properties of adrenaline, thyroxine, and histamine were mentioned in Section i i.i. 

The above two models together with Tabushi s cyclodextrin bis(histamine)23) are really elabolate ones, each having a substrate binding cavity, but their catalytic activities are yet far behind of those of natural enzymes. They suggest the difficulties associated with the design of a metal ion center inside of a cavity which activates both substrate and catalytic groups. 

Methionine produces cystine and taurine breaks down fats reduces blood cholesterol detoxifies the liver is an antioxidant and protects hair, skin, and nails. It is needed for synthesis of RNA and DNA and it assists in the breakdown of niacin, histamine, and adrenalin. It binds to heavy metals, such as lead and cadmium, and carries them out of the body. 

Serum albumin is the most abundant plasma protein (3.5-5.5%) and is responsible for the binding and transport of various metabolically and pharmacologically active molecules, e.g., bilirubin, uric acid, vitamin C, acetylcholine, cholinesterase, adenosine, aureomycin, barbiturate, Chloromycetin, digitonin, fatty acids, atabrine, neosilversalvarsan, penicillin, salicylate,/ -aminosalicylate, sulfonamide, streptomycin, acid dyes, histamine, triiodothyronine, and thyroxine (Bennhold, 1962 Putnam, 1975). Moreover, albumin tightly binds various metal ions, e.g., Zn (Giroux,... 

Another means to modify the retention of proteins in MIC is the inclusion of a competing complexing agent such as imidazole [24,82], histidine [82], histamine [83], glycine [31,32,83], ammonia [12], glutamate [65], or phosphate [65] in the mobile phase. Protein retention decreases with increasing concentration of the additive because of competition for the metal chelate binding sites. Imidazole is... 

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