Latent adenosine deaminase in mouse brain

Mustafa, S. Jamal; Tewari, C. P.

doi:10.1016/0005-2744(70)90017-3

Cited by 14 publications

(3 citation statements)

References 9 publications

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“…Activity of the adenosine deaminase of rat cerebral cortex dispersed in sucrose was found to be 115nmol/min per g of tissue, which is understandably greater than the activities of 55 and 70nmol/min per g of tissue measured by using lower substrate concentrations by Santos et al (1968) and by Mustafa (1972). The Km of 54-574uM is comparable with values reported for the adenosine deaminase of bovine placenta (40M; Maguire & Sim, 1971) and of calf intestinal mucosa (501uM; Chassey & Suhadolnik, 1967), but is distinct from that of the mouse brain, which has been reported to show two forms of adenosine deaminase with Km values of 6.4 and 11puM (Mustafa & Tewari, 1970).…”

Section: Assay and Occurrence Of The Deaminasesupporting

confidence: 80%

Rat cerebral-cortex adenosine deaminase activity and its subcellular distribution

Pull

McIlwain

1974

Biochemical Journal

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A radioisotopic assay for adenosine deaminase (EC 3.5.4.4) is described together with its application in investigating the activity of the enzyme in rat cerebral cortex. Activity of the adenosine deaminase was determined to be 115nmol/min per g of tissue, measured in isoosmotic sucrose dispersions of the neocortex, and to be 170nmol/min per g of tissue after treatment with Triton X-100. The enzyme was concluded to be largely cytoplasmic, with a K(m) of 54-57mum for adenosine. Action of the deaminase, and other aspects of the metabolism of adenosine in intact neocortical tissue, were quantitatively appraised on the basis of the newly determined characteristics.

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Section: Assay and Occurrence Of The Deaminasesupporting

confidence: 80%

Rat cerebral-cortex adenosine deaminase activity and its subcellular distribution

Pull

McIlwain

1974

Biochemical Journal

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“…However, no data on subcellular distribution were reported. Although it was originally reported that Triton X-100 revealed a latent ADase in mitochondria from mouse cerebral cortex (Mustafa & Tewari, 1970), subsequent studies indicted that the apparent increase in ADase was due to lysis of contaminating synaptosomes (Pull & Mcllwain, 1974).…”

Section: Discussionmentioning

confidence: 99%

Identification of a membrane adenosine deaminase binding protein from human placenta

Trotta¹

1982

Biochemistry

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“…The enzyme is frequently present in only small amounts (Phelan et al, 1970) where it occurs in tissues, and for this reason it might be argued that the enzyme does not play a very significant role in metabolism. However, recent work with mice (Mustafa & Tewari, 1970) suggests that in some tissues a considerable part of the total activity of the enzyme is present in a latent form; previous estimates of the amounts of this enzyme in various tissues may have to be revised.…”

Section: Discussionmentioning

confidence: 99%

Partial purification and properties of the common inherited forms of adenosine deaminase from human erythrocytes

Osborne

Sṕencer

1973

Biochemical Journal

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1. The partial purification of adenosine deaminase, types 1, 2 and 2-1, from human erythrocytes is described. 2. The isoenzyme components characteristic of the three forms of the enzyme were partially resolved by chromatography on DEAE-Sephadex. 3. Gel chromatography of the various forms of the enzyme gave estimates of the molecular weights in the range 30000-35000. 4. Electrophoresis in starch gels containing increasing percentages of starch did not reveal any differences in molecular weight between the genetic variants or their isoenzyme components. 5. Analytical isoelectric-focusing experiments in polyacrylamide gels gave the following pI values for the four isoenzyme components present in type 2-1 erythrocytes: 4.70, 4.83, 4.94 and 5.06. 6. All forms of the enzyme gave K(m) values for adenosine of about 30mum and K(i) values of about 8mum for the competitive inhibitor purine riboside. 7. Reaction rates of the type 1 and 2 enzymes were measured at different temperatures. Both enzymes gave values for the energy of activation for hydrolysis of adenosine of about 33.4kJ/mol (8kcal/mol). 8. Heat inactivation of all forms of the enzyme was markedly dependent on ionic strength, the rate of inactivation increasing with increasing ionic strength. The type 1 and type 2 forms of the enzyme differed significantly in their susceptibility to heat inactivation. From the variation of rates of inactivation with temperature, values were obtained for the energies of activation for the heat inactivation of both enzymes as follows: type 1 enzyme 275.5kJ/mol (65.9kcal/mol) and type 2 enzyme 241.6kJ/mol (57.8kcal/mol.).

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Latent adenosine deaminase in mouse brain

Cited by 14 publications

References 9 publications

Rat cerebral-cortex adenosine deaminase activity and its subcellular distribution

Rat cerebral-cortex adenosine deaminase activity and its subcellular distribution

Identification of a membrane adenosine deaminase binding protein from human placenta

Partial purification and properties of the common inherited forms of adenosine deaminase from human erythrocytes

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