Study Study of Complex of Complex Associates Between Associates Between Cationic Porphyrins and Cationic Porphyrins and Nucleosides or Nucleosides or Nucleotides Nucleotides Magdalena Makarska Magdalena Makarska , Stanisław , Stanisław Radzki Radzki Department of Inorganic Chemistry Department of Inorganic Chemistry Maria Curie-Skłodowska University in Lublin Maria Curie-Skłodowska University in Lublin
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Study of Complex Associates Between Cationic Porphyrins and Nucleosides or Nucleotides Magdalena Makarska, Stanisław Radzki Department of Inorganic Chemistry.
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StudyStudy of Complex of Complex Associates Between Associates Between
Cationic Porphyrins and Cationic Porphyrins and Nucleosides or Nucleosides or
NucleotidesNucleotides
Magdalena MakarskaMagdalena Makarska, Stanisław Radzki, Stanisław Radzki
Department of Inorganic ChemistryDepartment of Inorganic Chemistry
Maria Curie-Skłodowska University in LublinMaria Curie-Skłodowska University in Lublin
Scheme of interactions between porphyrins systemsScheme of interactions between porphyrins systems and nucleic bases and their derivativesand nucleic bases and their derivatives
Nucleic bases and their derivativesNucleic bases and their derivatives
adenineadenine
adenosineadenosine
ATPATP
guanineguanine
guanosineguanosine
GTPGTP
Nucleic bases and their derivativesNucleic bases and their derivatives
thyminethymineuraciluracil
uridineuridine
UTPUTP CTPCTP
cytosinecytosine
cytidinecytidinethymidinethymidine
The sites of metal fixation in nucleic basesThe sites of metal fixation in nucleic bases
adenineadenine guanineguanine
thyminethyminecytosinecytosine
uraciluracil
nL
2L P(N)...P(N) PN N+P
N][]P(N)[]P(N)[
K1-n
nn
]P[[N]...KKK...[N]KK+[N]K1
[N]...KKK...]N[KK]N[K=A n
n212
211
nn21n
2212110
Association constantsAssociation constants
A - absorbancy;A - absorbancy;εε0 0 - molar absorbancy index of initial porphyrin concentration;- molar absorbancy index of initial porphyrin concentration;
εε11 and K and K11, ..., etc. - molar absorbancy indexes and gradual stability constants, ..., etc. - molar absorbancy indexes and gradual stability constants
for complexes with stoichiometry 1:1, 1:2, ..., etc;for complexes with stoichiometry 1:1, 1:2, ..., etc;[N] - molar nucleic base (ligand) concentration;[N] - molar nucleic base (ligand) concentration;[P] - molar porphyrin concentration.[P] - molar porphyrin concentration.
ConclusionsConclusions11. The big differences in the results for particular nucleic agents, and first of all for different pH . The big differences in the results for particular nucleic agents, and first of all for different pH values indicate the diversification ofvalues indicate the diversification of interaction level of investigated systems. Such results can be interaction level of investigated systems. Such results can be
2. Interactions of H2. Interactions of H22TTMePP with nucleic bases are much stronger than interactions of TTMePP with nucleic bases are much stronger than interactions of
HH22TMePyP. Such effect is caused by the aniline group, much bigger than pyridyl group - TMePyP. Such effect is caused by the aniline group, much bigger than pyridyl group -
“stacking” (specific interactions consisting in forming of associates by reacting molecules) between “stacking” (specific interactions consisting in forming of associates by reacting molecules) between porphyrin and nucleic ligands is much more stronger for bigger compounds.porphyrin and nucleic ligands is much more stronger for bigger compounds.
3. The results show that the more stable associates are formed at lower pH value. Moreover, the 3. The results show that the more stable associates are formed at lower pH value. Moreover, the strength ofstrength of the obtained associates increases in series:nucleic base the obtained associates increases in series:nucleic base nucleoside nucleoside nucleotide, nucleotide,
although many departures from the rule are observed, because of high diversity and different pH although many departures from the rule are observed, because of high diversity and different pH values of investigatedvalues of investigated systems.systems.
4. The association constants for interactions between porphyrins and nucleic agents let us suppose 4. The association constants for interactions between porphyrins and nucleic agents let us suppose that by means of adequate porphyrin substituent groups and metal ion in porphyrin cave it would that by means of adequate porphyrin substituent groups and metal ion in porphyrin cave it would be possible to control the level of interactions between porphyrins and complicated DNA systems be possible to control the level of interactions between porphyrins and complicated DNA systems
and, probabely, introduce metalloporphyrins to the desirable place of DNA chain.and, probabely, introduce metalloporphyrins to the desirable place of DNA chain.
5. However, the substitution reactions proceeding on the metallic centres connected with nucleic 5. However, the substitution reactions proceeding on the metallic centres connected with nucleic acids are much more complicated, what is caused by the interactions of ligands with other groups, acids are much more complicated, what is caused by the interactions of ligands with other groups, as well as conformational changes in a macromolecule. Therefore all data obtained during study of as well as conformational changes in a macromolecule. Therefore all data obtained during study of porphyrin - DNA interactions should be particularly considered, because some porphyrin systems porphyrin - DNA interactions should be particularly considered, because some porphyrin systems
can join and interact with DNA in different ways, depending on neighbouring chemical can join and interact with DNA in different ways, depending on neighbouring chemical compounds. Very often the manner of interactions between reagents is determined by the kind of compounds. Very often the manner of interactions between reagents is determined by the kind of
reaction buffer and ionic strength connected with environment of investigated system.reaction buffer and ionic strength connected with environment of investigated system.
Metalloporphyrin molecule incorporated in DNA chainMetalloporphyrin molecule incorporated in DNA chain