Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1979-9-27
pubmed:abstractText
The three-dimensional structures of various penicillins and cephalosporins are compared to the spatial characteristics of glycylglycine and the tetrahedral adducts formed when a nucleophile attaches to the amide carbonyl carbon of this dipeptide. The dipeptide is taken to model the D-alanyl-D-alanine terminus of the precursors of bacterial cell-wall peptidoglycan cross-links. Least-squares fitting shows that the spatial match between the dipeptide and the antibiotic depends on the thiazolidine or dihydrothiazine ring conformation, as well as the conformation of the dipeptide. In general, the tetrahedral adducts fit somewhat better than the parent dipeptide. A previously unobserved 3-cephem conformer is found by molecular mechanics calculations to be less stable than the usual crystallographically observed conformer.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0022-2623
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
533-7
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Conformational analogy between beta-lactam antibiotics and tetrahedral transition states of a dipeptide.
pubmed:publicationType
Journal Article