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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1997-2-7
pubmed:abstractText
Mammalian livers have been reported to contain NADH- and NADPH-linked aquacobalamin reductases, which are distributed in both mitochondria and microsomes. The four aquacobalamin reductase isozymes have been purified and characterized from rat liver. It is unclear which aquacobalamin reductase among the four reductase isozymes participates in the synthesis of cobalamin coenzymes. To clarify the physiological roles of the aquacobalamin reductase isozymes, human mutant fibroblasts (cblC and cblA cells) with defects in cobalamin reductases involved in the coenzyme synthesis were used. In the cblC cells, the activity of the mitochondrial NADH-linked aquacobalamin reductase was reduced significantly, compared with normal human fibroblasts but the mitochondrial NADPH-linked enzyme was not. The reduced specific activity of the NADH-linked enzyme was not due to reduction in levels of the enzyme, but in its affinity for NADH. Although there was not a significant difference in the mitochondrial NADH-linked enzyme activity between normal and cblA cells, the activity of the mitochondrial NADPH-linked enzyme was not detectable in the mutant cells. These results indicate that the defects in the mitochondrial NADH- and NADPH-linked aquacobalamin reductases underlie cblC and cblA disorders, respectively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0022-3166
pubmed:author
pubmed:issnType
Print
pubmed:volume
126
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2947-51
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Mitochondrial NADH- or NADPH-linked aquacobalamin reductase activity is low in human skin fibroblasts with defects in synthesis of cobalamin coenzymes.
pubmed:affiliation
Department of Food and Nutrition, Kochi Women's University, Japan.
pubmed:publicationType
Journal Article