Linked Life Data

1911750

Source:http://linkedlifedata.com/resource/pubmed/id/1911750

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
1991-11-13
pubmed:abstractText
Using 125I-labeled phenol-alanine sparsomycin, an analogue of sparsomycin having higher biological activity than the unmodified antibiotic, we studied the requirements and the characteristics of its interaction with the ribosome. The drug does not bind to either isolated ribosomal subunits or reconstituted whole ribosomes. For sparsomycin binding to 70S and 80S ribosomes, the occupation of the peptidyltransferase P-site by an N-blocked aminoacyl-tRNA is a definitive requirement. The sparsomycin analogue binds to bacterial and yeast ribosomes with Ka values of around 10(6) M-1 and 0.6 x 10(6) M-1, respectively, but its affinity is probably affected by the character of the peptidyl-tRNA bound to the P-site. Chloramphenicol, lincomycin, and 16-atom ring macrolides compete with sparsomycin for binding to bacterial ribosomes, but streptogramins and 14-atom ring macrolides do not. Considering the reported low affinity of puromycin for bacterial ribosomes, this antibiotic is also a surprisingly good competitor of sparsomycin binding to these particles. In the case of yeast ribosomes, blasticidin is a relatively good competitor of sparsomycin interaction, but anisomycin, trichodermin, and narciclasin are not. As expected, puromycin is a poor competitor of the binding in this case. The results from competition studies carried out with different sparsomycin analogues reveal, in some cases, a discrepancy between the drug ribosomal affinity and its biological effects. This suggests that some intermediate step, perhaps a ribosomal conformational change, is required for the inhibition to take place.
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
8
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9642-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Biochemical and kinetic characteristics of the interaction of the antitumor antibiotic sparsomycin with prokaryotic and eukaryotic ribosomes.
pubmed:affiliation
Centro de Biologia Molecular, CSIC-UAM, Madrid, Spain.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't