Histidine decarboxylation

Histamine is produced by bacteria that decarboxylate histidine (jL-, ID, 14-17), an amino acid that is abundant in the muscle of scombroid fish and other marine fish such as mahimahi, the dolphin-fish ( 7, 18-25). Histidine decarboxylating bacteria have been isolated from spoiled marine fish (JL, 2, 25-27) and from fish... 

Histamine formation at 4°C was studied with resting cell suspensions of several histidine decarboxylating bacteria (Table III). Cells were harvested from cultures grown at 38°C in Trypticase soy broth (BBL, Cockeysville, MD.), suspended in 0.2 M phosphate buffer (pH 6.0) containing 0.1% histidine, and incubated anaerobically at 4°C for 21 days. After incubation, the cells were removed by filtration, and histamine was measured in the supernatant liquid. 

Le Jeune, C., Lonvaud-Funel, A., Ten Brink, B., Hofstra, H. van der Vossen, J.M.B.M. (1995). Development of detection system for histidine decarboxylating lactic acid bacteria based DNA probes, PCR and activity test. J. Appl. Bacteriol, 78, 316-326. 

As is the case for most enzyme activities measured in vitro, there is some doubt whether the histidine decarboxylase activities determined as above in various organs truly reflect the contribution of these organs to histidine decarboxylation in the intact animal. In vivo measurements give an overall picture of histidine decarboxylation in the living animal, but they can give little indication of the contribution made by individual organs. Moreover, the interpretation of such measurements is rendered difficult by bacterial decarboxylation of histidine in the gut, by metabolic destruction of histamine, and by the release of histamine from storage sites. Nevertheless, such measurements have provided much useful information, and they are particularly suited to the study of the effectiveness of histidine decarboxylase inhibitors in intact animals. As with in vitro methods the in vivo measurements can, in theory, be made either on the carbon dioxide or on the histamine formed in the decarboxylation. 

INHIBITION OF HISTIDINE DECARBOXYLATION in vitw Methods of Producing Inhibition... 

The use of tissue slices for experiments on histidine decarboxylation introduces the additional problem of the access of substrate, co-enzyme and inhibitors into the cells. In this connection, it should be noted that in practice the specificity of an enzyme within a cell may be increased by the specificity of the substrate-transporting system. Similar considerations apply to the in vivo inhibition of histidine decarboxylases there is, however, the additional possibility of modifying production of the apo-enzyme either by restricting the supply of amino acids or by altering the hormonal state of the animal. 

INHIBITION OF HISTIDINE DECARBOXYLATION ttt ffWO The in vivo production of histamine, and of other amines, in rats can be diminished by the use of pyridoxine-deficient diets, pyridoxine antagonists, or non-specific inhibitors such as semicarbazide > i >i . In female rats receiving a pyridoxine-deficient, histamine-free diet, the urinary output of histamine was reduced to about 50% of normal simultaneous administration of semicarbazide further reduced the histamine output to about 20% of normal. However, the histamine content of the tissues of these animals did not differ significantly from those of controls, except in the stomach where the histamine content dropped to a few per cent of normal. 

Histidine - Decarboxylation of histidine yields histamine (see here). In the stomach, histamine promotes secretion of hydrochloric acid and pepsin as digestion aids. Histamine is a potent vasodilator, released at sites of trauma, inflammation, or allergic reaction. Reddening of inflamed tissues is a result of local enlargement of blood capillaries. Antihistamines block binding of histamine to its receptors. Figure 21.23 shows that histidine is catabolized to glutamate. 

Histidine decarboxylation Lactococcus lactis ThdcA, ThdcP, ThdcB Trip et al. (2012)... 

Trip, H., Mulder, N. L., Lolkema, J. S. (2012). Improved acid stress survival of Lactococcus lactis expressing the histidine decarboxylation pathway of Streptococcus thermophilus CHCC1524. Journal of Biological Chemistry, 287, 11195-11204. 

Decarboxylase activity in fig histidine decarboxylated/g tissue/90 min. L(a) Equivalents according to Langemann and co-workers. ° ... 

Weissbach, H., Lovenberg, W. and Udenfriend, S., Characteristics of mammalian histidine decarboxylating enzymes, Biochim. Biophys. Acta 50, 177 (1961). 

Ganrot, P. O., Rosengren, A. M. and Rosengren, E., On the presence of different histidine decarboxylating enzymes in mammalian tissues, Experientia 17, 263 (1961). 

Histamine is a biogenic amine formed by L-histidine decarboxylation mediated by HDC (histidine decarboxylase) (EC EC 4.1.1.22) and naturally occurs in some fungi, marine, and plant species [6, 7]. It was isolated from aerial parts of Capsella bursa-pastoris (L.) Medik. (Brassicaceae), Lolium perenne L. (Poaceae) [8], and Spinacea oleracea L. (Chenopodiaceae) [7, 9]. This amine may act as an intermediate in many imidazole derivatives biosynthesis such as amides. 

Histidine decarboxylase from E. coli has a pH optimum near 4.0, while a similar enzyme assayed in Clostridium welchii has a pH optimum near 2.5. Extracts of acetone- or dioxane-treated C. welchii, however, have maximal rates of histidine decarboxylation at pH 4.5. The reason for the difference in pH optima of intact cells and extracts is conventionally attributed to pH effects on cell permeability, but other factors may be responsible. It is noteworthy in this connection that the Km of histidine is the same for both types of preparation. For years no cofactor could be found for this enzyme, but recently it was found that both pyridoxal phosphate and Fe+++ or Al are required. ... 

Histamine production. Growing cultures of P. acnes produce histamine (Allaker et al., 1986) and its synthesis increases with increasing growth rate. The growth of P. acnes is optimal at pH 6.0, while histamine synthesis has two pH-optima of 4.5 and 7.5. Histamine is formed as a result of histidine decarboxylation. 

Other examples of electrophilic metal catalysis are given under section 2.3.3.1. Electrophilic reactions are also carried out by enzymes which have an a-keto acid (pyruvic acid or a-keto butyric acid) at the transforming locus of the active site. One example of such an enzyme is histidine decarboxylase in which the N-terminal amino acid residue is bound to pyruvate. Histidine decarboxylation is initiated by the formation of a Schiff base by the reaction mechanism in Fig. 2.20. 

INHIBITION OF HISTIDINE DECARBOXYLATION in vitrO Methods of Producing Itdiibition... 

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