Linked Life Data

9760244

Source:http://linkedlifedata.com/resource/pubmed/id/9760244

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
1998-11-4
pubmed:abstractText
Purified rabbit and sheep sex hormone-binding globulins (SHBGs) were photolabeled by Delta 6-testosterone. The maximal levels of specific incorporation were respectively 0.33 and 0.30 mol of label/mol of homodimer. Tryptic cleavage of photolabeled SHBGs gave a single radioactive peptide for rabbit SHBG and two major radioactive peptides S1 and S2 for sheep SHBG. Edman sequencing of the photolabeled peptide of rabbit SHBG revealed a single sequence corresponding to peptidic fragment Leu-118-Lys-134. Subcleavage of this peptide with elastase led to a single radioactive peptidic fragment corresponding to dipeptide Met-133-Lys-134, identified by mass spectrometry, while deletion of the C-terminal residue with carboxypeptidase B showed that all the radioactivity remained on peptide Leu-118-Met-133, thus demonstrating that photolabeling occurred exclusively on Met-133, the only residue common to the two radioactive subcleaved peptides. Edman sequencing of peptides S1 and S2 of sheep SHBG showed a same single sequence corresponding to residues Gln-126-Arg-140 which contained no identifiable phenylthiohydantoin derivative at cycle 14, thus indicating that in both cases the corresponding Met-139 residue is the main site of photolabeling, as confirmed for peptide S1 by the presence at this cycle of a major peak of radioactivity while in peptide S2 the photoattachment of Delta 6-testosterone was found labile in the conditions of sequencing. The photolabeled peptide S1 was characterized by mass spectrometry which showed the covalent fixation of one mole of Delta 6-testosterone and the presence of a biantennary oligosaccharide attached at Asn-133, which suggests that the steroid-binding site is probably not deeply buried in the SHBG homodimer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
6
pubmed:volume
37
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14088-97
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Photoaffinity labeling of homologous Met-133 and Met-139 amino acids of rabbit and sheep sex hormone-binding globulins with the unsubstituted Delta 6-testosterone photoreagent.
pubmed:affiliation
Institut National de la Santé et de la Recherche Médicale, Unité INSERM U 329, Pathologie Hormonale Moléculaire, Hôpital Debrousse, Lyon, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't