Journal article
Interactions of porphyrins and transfer RNA
Biochimica et biophysica acta. Gene structure and expression, Vol.950(2), pp.118-131
1988
DOI: 10.1016/0167-4781(88)90004-8
PMID: 3382660
Abstract
The interactions of the free base porphyrin, tetra-(4
N-methylpyridyl)porphyrin and its copper(II), manganese(III) and zinc(II) complexes with brewer's yeast type V phenylalaninyl tRNA were evaluated by UV-visible spectroscopy, circular dichroism and melting temperature studies over a range of magnesium ion concentrations and ionic strengths. Scatchard analysis of absorption spectra of the porphyrins in the presence of tRNA showed the free base, copper and zinc porphyrins to have binding constants of 7.3 · 10
7, 1.7 · 10
6 and 2.3 · 10
8, respectively; the manganese(III) complex did not demonstrate changes in its electronic spectra that enable the calculation of a binding constant. The results of the spectroscopic studies indicate a mode of binding for the free base, copper(II) and zinc(II) complexes that is neither intercalative nor simply outside electrostatic. The magnitude of the binding constants and the UV-visible results support intercalation, but the analyses of the thermal denaturation studies and the circular dichroism evaluations suggest that the porphyrins are associating at a single site in a fold of the tertiary structure of the tRNA close to several crucial hydrogen bonds, perhaps in the vicinity of the P10 loop. That the manganese(III) complex does not bind in this site points to constraints on the axial thickness of a molecule that may be accommodated in this locus.
Details
- Title: Subtitle
- Interactions of porphyrins and transfer RNA
- Creators
- Natalie Foster - Department of Chemistry and Institute for Health Sciences, Lehigh University, Bethlehem, PA USAArun K Singhal - Department of Chemistry and Institute for Health Sciences, Lehigh University, Bethlehem, PA USAMarion W Smith - Department of Chemistry and Institute for Health Sciences, Lehigh University, Bethlehem, PA USANora G Marcos - Department of Chemistry and Institute for Health Sciences, Lehigh University, Bethlehem, PA USAKeith J Schray - Department of Chemistry and Institute for Health Sciences, Lehigh University, Bethlehem, PA USA
- Resource Type
- Journal article
- Publication Details
- Biochimica et biophysica acta. Gene structure and expression, Vol.950(2), pp.118-131
- DOI
- 10.1016/0167-4781(88)90004-8
- PMID
- 3382660
- NLM abbreviation
- Biochim Biophys Acta
- ISSN
- 0167-4781
- eISSN
- 1879-2634
- Publisher
- Elsevier B.V
- Language
- English
- Date published
- 1988
- Academic Unit
- Surgery; Cardiothoracic Surgery
- Record Identifier
- 9984051519702771
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