Altered properties of human t-lymphoblast soluble low Km 5'-nucleotidase: Comparison with B-lymphoblast enzyme
dc.contributor.author | Madrid-Marina, Vicente | en_US |
dc.contributor.author | Lestan, Boris | en_US |
dc.contributor.author | Nowak, Paul J. | en_US |
dc.contributor.author | Fox, Irving H. | en_US |
dc.contributor.author | Spychala, Jozef | en_US |
dc.date.accessioned | 2006-04-10T15:52:08Z | |
dc.date.available | 2006-04-10T15:52:08Z | |
dc.date.issued | 1993-03 | en_US |
dc.identifier.citation | Madrid-Marina, Vicente, Lestan, Boris, Nowak, Paul J., Fox, Irving H., Spychala, Jozef (1993/03)."Altered properties of human t-lymphoblast soluble low Km 5'-nucleotidase: Comparison with B-lymphoblast enzyme." Leukemia Research 17(3): 231-240. <http://hdl.handle.net/2027.42/30943> | en_US |
dc.identifier.uri | http://www.sciencedirect.com/science/article/B6T98-4BP9V2P-2T/2/4d6945d18a6cc0a04b56a6fd4dbf2dde | en_US |
dc.identifier.uri | https://hdl.handle.net/2027.42/30943 | |
dc.identifier.uri | http://www.ncbi.nlm.nih.gov/sites/entrez?cmd=retrieve&db=pubmed&list_uids=8450671&dopt=citation | en_US |
dc.description.abstract | Soluble low Km 5'-nucleotidases have been purified from human cultured T- and B-lymphoblasts to compare their properties and to examine the mechanism of different rates of nucleotide dephosphorylation. The enzyme from B-lymphoblasts (MGL-8) was 4385-fold purified with a specific activity of 114 [mu]mol/min/mg, while the enzyme from T-lymphoblasts (CEM, MOLT-4) was 4355-fold purified with a specific activity of 35 [mu]mol/min/mg. The activity of both enzymes have an absolute requirement for Mg++. The B-cell enzyme has maximum activity with Mg2+ > Mn2+ > Co2+, while the T-cell enzyme had maximum activity with Co2+ > Mn2+ > Mg2+. The optimum activity was at pH 7.4-9.0 for the B-cell enzyme and pH 9.0 for the T-cell enzyme. Substrate specificity was the same for both enzymes with the following relative Vmax values: CMP > UMP > dUMP > dCMP > dAMP > IMP > GMP > dIMP > dGMP. The Km values for AMP and IMP were 12 and 25 [mu]M for the B-cell enzyme, and 7.0 and 12 [mu]M for the T-cell enzyme. ATP and ADP are competitive inhibitors of these enzymes with apparent Ki values of 100 and 20 [mu]M for the B-cell enzyme, and 44 [mu]M and 8 [mu]M for the T-cell enzyme, respectively. The apparent molecular mass by gel filtration column chromatography is 145 kD for the B-cell enzyme and 72 kDa for the T-cell enzyme. The subunit molecular masses by Western blots are 69.2 kD for both enzymes.These properties suggest that the B-lymphoblast enzyme is identical or similar to the enzyme from human placenta. However, the T-cell enzyme has some different properties. We conclude that these differences plus a lower content of low Km 5'-nucleotidase in T-cells may account for the decreased ability of T-lymphoblasts to dephosphorylate nucleotides and may contribute to the selective cytotoxicity of deoxyribonucleosides for T-lymphoblasts as compared to B-lymphoblasts. | en_US |
dc.format.extent | 972756 bytes | |
dc.format.extent | 3118 bytes | |
dc.format.mimetype | application/pdf | |
dc.format.mimetype | text/plain | |
dc.language.iso | en_US | |
dc.publisher | Elsevier | en_US |
dc.title | Altered properties of human t-lymphoblast soluble low Km 5'-nucleotidase: Comparison with B-lymphoblast enzyme | en_US |
dc.type | Article | en_US |
dc.rights.robots | IndexNoFollow | en_US |
dc.subject.hlbsecondlevel | Oncology and Hematology | en_US |
dc.subject.hlbtoplevel | Health Sciences | en_US |
dc.description.peerreviewed | Peer Reviewed | en_US |
dc.contributor.affiliationum | The University of Michigan, Department of Internal Medicine, Division of Rheumatology, Ann Arbor, MI 48109, U.S.A. | en_US |
dc.contributor.affiliationum | The University of Michigan, Department of Internal Medicine, Division of Rheumatology, Ann Arbor, MI 48109, U.S.A. | en_US |
dc.contributor.affiliationum | The University of Michigan, Department of Internal Medicine, Division of Rheumatology, Ann Arbor, MI 48109, U.S.A. | en_US |
dc.contributor.affiliationum | The University of Michigan, Department of Internal Medicine, Division of Rheumatology, Ann Arbor, MI 48109, U.S.A. | en_US |
dc.contributor.affiliationum | The University of North Carolina, Department of Pharmacology, Chapel Hill, NC 27599, U.S.A.; University of Michigan, Department of Internal Medicine, Division of Rheumatology, Ann Arbor, MI 48109, U.S.A. | en_US |
dc.identifier.pmid | 8450671 | en_US |
dc.description.bitstreamurl | http://deepblue.lib.umich.edu/bitstream/2027.42/30943/1/0000614.pdf | en_US |
dc.identifier.doi | http://dx.doi.org/10.1016/0145-2126(93)90006-7 | en_US |
dc.identifier.source | Leukemia Research | en_US |
dc.owningcollname | Interdisciplinary and Peer-Reviewed |
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