Linked Life Data

1985912

Source:http://linkedlifedata.com/resource/pubmed/id/1985912

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1991-2-14
pubmed:abstractText
Human placenta hexokinase type I was previously shown to be present in two subtypes with similar isoelectric points but different molecular masses of 112 and 103 kDa, respectively. In order to exclude that these subtypes arise by artifact(s) occurring during the protein purification, we have developed a single-step immunoaffinity chromatography for the isolation of microgram quantities of hexokinase. The results obtained confirmed the presence of both hexokinase subtypes in human placenta. By Northern blot analysis a single mRNA species that hybridized with a hexokinase-I cDNA was found to be present in human placenta. Furthermore, in vitro translation of placenta mRNA in a rabbit reticulocyte lysate followed by hexokinase immunoprecipitation and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography showed that only one hexokinase with apparent molecular mass of about 112 kDa is expressed in this tissue and suggests a post-translational modification as a probable cause of hexokinase I microheterogeneity. To further investigate this point we have purified the high and low Mr hexokinase and determined their NH2-terminal sequences. The results obtained show that when compared with the amino acid sequence deduced from a cDNA the high Mr hexokinase starts at amino acid 11 while the low Mr hexokinase starts at amino acid 103. Since the first 10 amino acids are involved in the binding of hexokinase to mitochondrial porin these data provide an explanation both for the inability of these hexokinases to bind to mitochondria and for their differences in Mr.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
266
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
502-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Human hexokinase type I microheterogeneity is due to different amino-terminal sequences.
pubmed:affiliation
Istituto di Chimica Biologica G. Fornaini, Università degli Studi, Urbino, Italy.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't