Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1997-3-3
pubmed:abstractText
The mitochondrial general processing peptidase (MPP) in plant mitochondria constitutes an integral part of the cytochrome bc1 complex of the respiratory chain. Here we present a characterization of this bifunctional complex from spinach leaf mitochondria. The purified MPP/bc1 complex has a molecular mass of 550 kDa, which corresponds to a dimer. Increased ionic strength results in partial dissociation of the dimer as well as loss of the processing activity. Micellar concentrations of nonionic and zwitterionic detergents stimulate the activity by decreasing the temperature optimum of the processing reaction, whereas anionic detergents totally suppress the activity. MPP is a metalloendopeptidase. Interestingly, hemin, a potent regulator of mitochondrial and cytosolic biogenesis and inhibitor of proteosomal degradation, inhibits the processing activity. Measurements of the processing activity at different redox states of the bc1 complex show that despite bifunctionality of the MPP/bc1 complex, there is no correlation between electron transfer and protein processing.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0145-479X
pubmed:author
pubmed:issnType
Print
pubmed:volume
28
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
285-92
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Characterization of the bifunctional mitochondrial processing peptidase (MPP)/bc1 complex in Spinacia oleracea.
pubmed:affiliation
Department of Biochemistry, Arrhenius Laboratories for Natural Sciences, Stockholm University, Sweden.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't