Comparative and immunochemical studies of bovine adenosine deaminases

Lee, P.C.; Fisher, James R.; Ma, Pujades

doi:10.1016/0305-0491(71)90051-4

Cited by 7 publications

(3 citation statements)

References 11 publications

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“…The Km values of ADA1 for adenosine and deoxyadenosine are similar (50–70 µ m ), activity is optimal at neutral pH, and enzyme activity is fully inhibited by 100 µ m erythro‐9‐(2‐hydroxynon‐3‐yl)adenine (EHNA) [18]. Some tissue‐associated variant proteins thus characterized have been studied extensively [14,15,26–30]. Multiple mutations of the ADA1 monomer have been identified, and the mutation or deficiency of these proteins is associated with severe combined immunodeficiency (SCID).…”

Section: Discussionmentioning

confidence: 99%

Macrophages are a source of extracellular adenosine deaminase-2 during inflammatory responses

Conlon

Law

2004

Clinical and Experimental Immunology

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SUMMARYSerum activity of the adenosine deaminase (ADA) isozyme, ADA2, has been reported to be elevated during various disease states. Macrophages have been suggested as the cellular source of extracellular ADA activity because they are one of the only cell types in which intracellular ADA2 activity has been measured, but extracellular secretion has never been demonstrated. Rat primary peritoneal macrophages (PPMs) and peripheral blood monocytes (PBMs) were harvested and incubated for 18 h in RPMI supplemented with horse serum. PPM and PBM lysates were assayed for intracellular ADA activity (ammonia production). In vitro and in vivo extracellular ADA activities were measured in media and rat serum, respectively. Activity of ADA1 was confirmed by selective inhibition with erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA). ADA2 activity was inhibited by 2 ¢ -deoxycoformcin only, and was increased at a low pH (6·5). Activity of both ADA isozymes was found in PPMs and PBMs, and their media. In a separate group of rats, peritonitis was induced by ip insertion of 400 mg/kg caecal slurry. PPMs were harvested 24 h later and incubated for 18 h. In PPMs from rats with peritonitis both isozymes were elevated by a similar proportion. In contrast, media from these PPMs had a lower ADA1 and a higher ADA2 activity compared to PPMs from nonseptic rats. This resulted in a greater proportion of ADA2 in media. The isozyme proportions in serum from septic rats more closely resembled that of the PPM media. The response of PBM was small relative to that of PPM. These results suggest that macrophages are a significant source of extracellular ADA isozymes, the activity of which increases during an inflammatory response. Because extracellular isozymes profiles differ from cellular concentrations, the data also suggest differential release of each isozyme from PPMs.

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Section: Discussionmentioning

confidence: 99%

Macrophages are a source of extracellular adenosine deaminase-2 during inflammatory responses

Conlon

Law

2004

Clinical and Experimental Immunology

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“…This 35,000-dalton catalytic unit can combine with a 200,000-dalton, enzymati cally inactive, dimeric glycoprotein (combin ing protein, CP) to give rise to 280,000-dalton ADA isozymes (ADAi+cp) [7][8][9][10][11][12][13][14][15][16]20]. The 35,000-and 280,000-dalton ADA isozymes account for virtually all the ADA activity in most mammalian species.…”

Section: Introductionmentioning

confidence: 99%

Comparison and Possible Homology of Isozymes of Adenosine Deaminase in Aves and Humans

Ratech

Thorbecke

Meredith

et al. 1981

Enzyme

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Two kinetically distinct adenosine deaminase (ADA) isozymes with different molecular weights (35,000 and 100,000 daltons) are found in chicken liver in approximately equal amounts. The 100,000-dalton ADA has a markedly higher K(m) for adenosine and a markedly lower deaminating activity for deoxyadenosine relative to adenosine than does the 35,000-dalton ADA. A 100,000-dalton ADA isozyme has only recently been detected in mammalian tissues, where, in contrast to the chicken, it is only a trace component of total ADA activity. The human 100,000-dalton ADA isozyme, compared to the human 35,000- dalton ADA isozyme, has been reported to have a higher K(m), a lower pH optimum, and a greater resistance to inhibition by erythro-9-(2-hydroxy-2-nonyl) adenine (EHNA). The similarity in K(m)s of the 100,000-dalton ADA isozyme in man and aves led us to hypothesize that these isozymes might be descended from a common ancestor and therefore also be similar as to other kinetic parameters. We now report that the chicken 100,000-dalton ADA, like the human 100,000-dalton isozyme, has a lower pH optimum and a greater resistance to inhibition by EHNA than does the avian or human 35,000-dalton isozyme. In addition, the avian 100,000-dalton isozyme is relatively resistant to inhibition by deoxycoformycin and has a cathodal rather than an anodal electrophoretic mobility at pH 6.5. Conversely, we report that the human 100,000-dalton ADA isozyme, similar to the avian 100,000-dalton ADA, has markedly lower relative deaminating activity for deoxyadenosine than does the 35.000- dalton ADA human isozyme. Thus, despite the marked difference in the relative amounts of the 100,000- and 35,000-dalton ADA isozymes in man as compared to aves, the 100.000- dalton ADA isozymes from both species exhibit several similar kinetic properties, all of which are different from those of the 35,000-dalton ADA isozymes. We also report using a new sensitive assay, relative rates of degradation by the two chicken isozymes of several naturally occurring modified adenine nucleosides which are inhibitory to in vitro human lymphocyte proliferation.

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“…Considerable interest has been given to the problem of the existence of multiple molecular forms of the enzyme in different tissues of several species. The observed multiplicity can be accounted for by cistronic variation (Edwards et al, 1971;Lee et al, 1971) or conformational changes (Ressler, 1969) of a common polypeptide chain. The onelocus concept was strongly substantiated by the finding in human tissue extracts of two molecular species: large (EL; mo1.W.…”

Section: Discussionmentioning

confidence: 99%

Adenosine deaminase in the pig: tissue‐specific patterns and expression of the silent ADA⁰ allele in nucleated cells

Widar¹,

Ansay²

1975

Animal Blood Groups and Biochemical Genetics

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By means of polyacrylamide gel and cellulose acetate enzymo-electrophoresis, the authors have studied tissue-specific isozymes of adenosine deaminase in the pig; these have been correlated to the erythrocytic ABO-like polymorphism. The enzyme product of the ADA0 gene was detected in nucleated cells; the absence of the ADA0 gene product in erythrocytes was tentatively accounted for by an increased in vivo lability.

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Comparative and immunochemical studies of bovine adenosine deaminases

Cited by 7 publications

References 11 publications

Macrophages are a source of extracellular adenosine deaminase-2 during inflammatory responses

Macrophages are a source of extracellular adenosine deaminase-2 during inflammatory responses

Comparison and Possible Homology of Isozymes of Adenosine Deaminase in Aves and Humans

Adenosine deaminase in the pig: tissue‐specific patterns and expression of the silent ADA⁰ allele in nucleated cells

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Comparative and immunochemical studies of bovine adenosine deaminases

Cited by 7 publications

References 11 publications

Macrophages are a source of extracellular adenosine deaminase-2 during inflammatory responses

Macrophages are a source of extracellular adenosine deaminase-2 during inflammatory responses

Comparison and Possible Homology of Isozymes of Adenosine Deaminase in Aves and Humans

Adenosine deaminase in the pig: tissue‐specific patterns and expression of the silent ADA0 allele in nucleated cells

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Adenosine deaminase in the pig: tissue‐specific patterns and expression of the silent ADA⁰ allele in nucleated cells