Hypotaurine

Metabolism of Other Amino Acids /3-Alanine metabolism Taurine and hypotaurine metabolism Aminophosphonate metabolism Selenoamino acid metabolism Cyanoamino acid metabolism D-Glutamine and D-glutamate metabolism... 

This enzyme [EC 1.13.11.19] catalyzes the reaction of cysteamine with dioxygen to produce hypotaurine. The protein uses iron ions as cofactors. 

Fig. 24-25), another component of nervous tissue. Cysteic acid can arise in an alternative way from O-acetylserine and sulfite (reaction 1, Fig. 24-25), and taurine can also be formed by decarboxylation of cysteine sulfinic acid to hypotaurine and oxidation of the latter (reaction m). Cysteic acid can be converted to the sulfolipid of chloroplasts (p. 387 Eq. 20-12). 

A considerable amount of work on the synthesis and crystal structure of peptides containing a p-aminoethane sulfonamide moiety, i.e. taurine (Tau), has been described by Calcagni et aj [7,ii5-ii7] an(j Diaz et alJ118] and a p-aminoethane sulfinamide (hypotaurine) moiety by Moree et alJ111,112,119,120 ... 

Altieri, D.C. 2003. Validating survivin as a cancer therapeutic target. Nat. Rev. Cancer 3, 46-54. Alvarez, J.G. and Storey, B.T. 1983. Taurine, hypotaurine, epinephrine and albumin inhibit lipid peroxidation in rabbit spermatozoa and protect against loss of motility. Biol. Reprod 29, 548-555. Ambani, L.M., Van Woert, M.H., and Murphy, S. 1975. Brain peroxidase and catalase in Parkinson s disease. Arch. Neurol. 32, 114-118. 

Adociaquinones A (492) and B (493) and 3-ketoadociaquinone A (494) were obtained from a sponge Adocia sp. collected in Truk Lagoon (398). Compounds 492 and 493 were synthesized from xestoquinone (399) by heating with hypotaurine. Adociaquinone B (493) was mildly cytotoxic. Polycarpamines A-E (495-499) with a rare, sulfur-containing benzenoid... 

Rhemrev et al. (RIM) measured TAC of human seminal plasma by ABTS + decoloration at 37°C and distinguished fast TRAP (decolorization measured 10 sec after addition of the sample) and slow TRAP (decolorization measured between 10 and 300 sec after addition of the sample). One of the compounds contributing to the slow TRAP is tyrosine, present in seminal plasma at high concentrations (Table 5). Another contributor to the slow TRAP is hypotaurine, but the contribution of tyrosine is more important due to its higher concentration in seminal plasma (2.12 mM vs. 36 /rM) (R14, V8). 

Serum urine CKD Healthy subjects 7 patients 15 CE-TOF MS Carnosine, hypotaurine, adenosine, guanine (urine) hypotaurine, and taurine (serum) (27)... 

Figure 14.7. Pathways for the synthesis of taurine from cysteine. Cysteine sulfinate decarboxylase, EC 4.1.1.29 cysteic acid decarboxylase, EC 4.1.1.29 (glutamate decarboxylase, EC 4.1.1.15) cysteine oxidase, EC 1.13.11.20 cysteamine oxygenase, EC 1.13.11.19 and hypotaurine oxidase, EC 1.8.1.3. Relative molecular masses (Mr) cysteine, 121.2 cysteamine, 77.2 cysteine sulfinic acid, 153.2 cysteic acid, 169.2 hypotaurine, 109.1 and taurine, 125.1.

Alvarez JG, Storey BT. 1983. Taurine, hypotaurine, epinephrine and albumin inhibit lipid peroxdation in rabbit spermatozoa and protect against loss of motility. Biol. Reprod. 29 548-55... 

Hypotaurine has been oxidised to taurine (2-aminoethanesulfonic acid) by 02( Ag) which has been photochemically produced using methylene blue as sensitizer. In the presence of azide, a well known quencher of 02( Ag), rather than the expected inhibition, an activating effect is observed, and this has been attributed to the generation of the azidyl radical. It is supposed that this radical participates in a strong one-electron abstraction process with the hypotaurine resulting in its oxidation. 

Changes in biological activity distinguish the sulfonic from the carboxylic acids. Broadly speaking, the sulfonic acids as a class are generally not biologically active. Exceptions are certain complex dyes or trypanocides (Trypan blue, suramin, etc.) and sulfonic amino acids such as taurine and hypotaurine for which an active transport mechanism exists. For carboxylic acids the situation depends on whether the carboxylic function is introduced in small or large molecules. 

Fig. 3. Synthesis of taurine from cysteine. The major pathway for the formation of taurine is via hypotaurine.

It has been mentioned above that there are few naturally occurring sulphonic acids. One notable exception is taurine (6), which is formed biosynthetically in several steps. One of these steps involves the oxidation of either cysteine sulphinic acid or hypotaurine (both of which contain a sulphinic acid group) to sulphonic acids. This reaction is, of course,... 

Incubation of embrionic calf liver with 35S-labelled sodium sulphite, sodium pyruvate and sodium glutamate at 38 °C under nitrogen resulted in formation of 35S-cysteinesulphinic acid133,134. 35S-hypotaurine has also been isolated, but taurine-35S and cystine-35S have not been found. In the presence of serine, the yield of 35S-cysteinesulphinic acid was smaller. Organic 35S compounds without amino groups have also been formed in the same experiment. In the conditions employed in this bioexperiment cysteinesulphinic acid is not reduced to cystine-3 5S, although such reduction was found possible in vivo. 

The aerobic metabolism of cystine-3 5S by chicken embryo, investigated166 both in vivo and in vitro, resulted in the formation of cystinedisulphoxide-35S (in vitro only), [35S] cystinesulphinic acid, [35S] cysteic acid, [35S]taurine and sulphate-35S. Hypotaurine has been detected neither in vivo nor in vitro. This indicates that, contrary to what had been observed in mammalian liver, hypotaurine is not the precursor of taurine in chicken embryo (equation 86). The enzyme decarboxylase, which effectively decarboxylates [35S]cysteic acid, does not act on cysteinesulphinic acid. Sulphate-35S may be produced also by the desulphination of cysteinesulphinic acid (equation 87) or from some other... 

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