Peculiarities of interaction of porphyrins with tRNA at low ionic strength.
The interaction of meso-tetra-(4N-oxyethylpyridyl)porphyrin (TOEPyP4) and its Zn(II)-, Cu(II)-, Mn(III)-derivatives with tRNA from E.Coli at low ionic strength (micro=0.02M) was studied using UV/Vis spectrophotometry and Circular Dichroism (CD) methods. An unusual Induced Circular Dichroism (ICD) spectra profile of the ZnTOEPyP4-tRNA complex is found. It is demonstrated that ZnTOEPyP4 is ordered in a stack, not only on helical sites, but also on loops of a hairpin form of tRNA. TOEPyP4 and CuTOEPyP4 are able to intercalate in the helical sites of this form of tRNA. MnTOEPyP4 interacts with tRNA via external non-ordered mechanism. It is established that all porphyrins are bound with tRNA more strongly than with DNA.
Dalyan
Y
Y
Yerevan State University, Faculty of Physics, Department of Molecular Physics, 1, A.Manoogian St., 0025, Yerevan, Armenia. yeva@ysu.am
Vardanyan
I
I
Chavushyan
A
A
Balayan
G
G
D002942:Circular Dichroism; D003300:Copper / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D009994:Osmolar Concentration; D011166:Porphyrins / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding; D012343:RNA, Transfer / Q000737:chemistry* / Q000378:metabolism; D015032:Zinc / Q000737:chemistry
D011166:Porphyrins; D008345:Manganese; D003300:Copper; D012343:RNA, Transfer; D015032:Zinc