Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.4.4 (adenosine deaminase)
 5,136 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neurons immunoreactive for the enzyme adenosine deaminase (ADA) in the posterior basal hypothalamus of the rat have a distribution pattern similar to those immunoreactive for histidine decarboxylase (HDC) and are particularly numerous in the tuberal (TM), caudal (CM) and postmammillary caudal (PCM) hypothalamic magnocellular nuclei which harbor neurons containing glutamic acid decarboxylase (GAD). The extent to which these enzymes coexist within neurons of these hypothalamic regions was examined using either serial sections or simultaneous immunostaining for ADA and HDC or GAD in the same section. Analysis of serial sections revealed neuronal coexistence of ADA with HDC or GAD in both TM and CM. In addition some neurons in CM, the only area examined for triple coexistence, were found to contain all three enzymes. In sections processed for ADA simultaneously with HDC or GAD, nearly all ADA-immunoreactive neurons in TM, CM, and PCM as well as those scattered between these nuclei were found to contain HDC, and nearly all contained GAD. Exceptions to this, however, were small cells located lateral to the posterior arcuate nucleus, which appeared to contain ADA but not HDC, and large neurons located at the anterior extreme of TM, which appeared to contain ADA but not GAD. The relatively few ADA- compared with GAD-containing neural systems in brain, together with the presence of ADA in GAD-containing hypothalamic magnocellular neurons, which appear to have widespread projections throughout the brain, indicate that ADA may be a convenient immunohistochemical marker for anatomical investigations of these projections.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Coexistence of adenosine deaminase, histidine decarboxylase, and glutamate decarboxylase in hypothalamic neurons of the rat. 407 33

Deaminations of adenine and adenosine by pattern strains of 24 staphylococcal species, were tested. During 3 hours of incubation of the suspensions of 8 staphylococci with adenine the liberation of ammonia occurred. The same staphylococci accumulated ammonia in the incubation medium with adenosine. The Staphylococcus intermedius PCM 2405 strain as opposite to the Staphylococcus aureus 536 strain in the media with adenine or adenosine accumulated hypoxanthine or inosine, respectively and ammonia. These results indicated that adenine deaminase (adenase) and adenosine deaminase activities were associated with the cells of the Staphylococcus intermedius PCM 2405 strain. Staphylococci were heterogeneous within three species groups with respect to adenine and adenosine deaminations. Adenine and adenosine determinations were absent in staphylococci belonging to the Staphylococcus simulans species group.
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PMID:[Deamination of adenine and adenosine in staphylococci]. 955 42

Oxanosine 3r, 5-amino-3-beta-(d-ribofuranosyl)-3H-imidazo[4,5-d][1,3]oxazine-7-one, was isolated as a novel nucleoside antibiotic in 1981 from Streptomyces capreolus MG265-CF3. Oxanosine became relevant in toxicology in 1996 with the discovery that it is formed in nitrosative guanosine deamination. As part of studies of the mechanism of oxanosine formation, the synthesis was attempted of [7- 18O]oxanosine by enzymatic 16O/18O-exchange with adenosine deaminase (ADA) in analogy to the synthesis of [6- 18O]guanosine from 2-amino-6-chloropurine. Unexpectedly, it was discovered that the incubation of oxanosine 3r with ADA in sodium phosphate buffer (pH = 7.4) results in 1-beta-(d-ribofuranosyl)-5-ureido-1H-imidazole-4-carboxylic acid 4r. The reaction of the 2'-deoxyribose derivative 3d forms 4d in analogy. The reaction products were separated by preparative RP-HPLC and characterized by LC/MS and MS/MS analyses and UV/vis and NMR spectroscopy, and NMR assignments were corroborated by GIAO and GIAO-PCM calculations. Reaction in H2 18O leads to 18O-incorporation at C7. The hydrolysis of 3 to 4 can be rationalized on the basis of the known mode of action of ADA, and an explanation is provided for ADA's accomplishment of the "usual" substitution at C6 of adenosine (addition to the exocyclic bond) and the "lactone hydrolysis" of oxanosine (addition to the endocyclic double bond). The Michaelis-Menten constant of Km = 1.0 (+/-0.2) mM was measured for oxanosine. Implications are discussed for studies of nitrosative deamination of nucleosides, nucleotides, and oligonucleotides.
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PMID:Oxanosine is a substrate of adenosine deaminase. Implications for the quest for a toxicological marker for nitrosation activity. 1635 73