Linked Life Data

8547339

Source:http://linkedlifedata.com/resource/pubmed/id/8547339

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-2-22
pubmed:abstractText
We previously isolated cDNA for mouse coproporphyrinogen oxidase (CPO) and provided evidence for the induction of mRNA during differentiation of murine erythroleukemia cells (Kohno et al. (1993) J. Biol. Chem. 268, 21359-21363). To better understand the structure and the mechanisms of reaction of the enzyme, we expressed mouse CPO in Escherichia. coli and purified it to a homogeneity. Analysis of the metal content revealed that the recombinant mouse CPO contains one copper atom per polypeptide chain. When the bacterial cells were treated with D-penicillamine, a copper chelator, formation of the active CPO was partially reduced. Addition of Cu2+ in minimal medium resulted in 6-fold higher level of CPO activity. These results suggest that expression of active mouse CPO in E. coli depended on the presence of Cu2+ in the culture medium. To elucidate the apparent involvement of Cu2+ in enzyme function, a series of mutant enzymes, whose highly conserved histidine and cysteine residues were individually converted to alanine residue, were prepared by site-directed mutagenesis. Mutant enzymes were expressed in E. coli and their activities examined. Mutation at histidine 158 resulted in a complete loss of enzyme activity, yet the enzyme protein was expressed at a comparable level. Concomitantly, only a trace amount of Cu2+ was detected in the purified H158A enzyme. We propose that mouse CPO is copper-containing enzyme and Cu2+ interacts with a conserved histidine residue.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
1292
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
156-62
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Mouse coproporphyrinogen oxidase is a copper-containing enzyme: expression in Escherichia coli and site-directed mutagenesis.
pubmed:affiliation
Department of Hygiene, Kansai Medical University, Osaka, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't