Spectroscopic Studies Of TMPyP And Interaction With DNA

Porphyrins is a general term of the homologue and derivative of porphine with substituting groups at the outside ring, becoming metalloporphyrins promptly after two protons on its nitrogen are replaced by the metal ion. This is one kind widely exists in the plants and animals, has the special activity. The heme, the chlorophyll is its typical representative. As early as in 1930s, porphyrins have been under intensive study. And now they have been widely used in many fields of biochemistry, medicine, analytical chemistry, bionics . TMPyP is one of porphyrins that many people pay attention to it in early.Since 1979, Feil and co-workers reproted that TMPyP and its metal derivatives can intercalate into DNA, the interaction of TMPyP with a variety of DNA, RNA and other biological macromolecules has been paid much attention. And that have a good application prospect in Biological Sciences. The nature of TMPyP has been studied in detail from recent years, and there is much significance for Life Processes Understanding.By using UV-visible spectroscopy, Fluorescence Spectroscopy, Circular Dichroism, Raman spectroscopy , we studied the ionic strength and solvent effect on the structure of TMPyP, the binding mode of TMPyP and ctDNA , the mode change by the salt ions.The structure of TMPyP changes with solvent-induced, the organic component - water mixtures from tetrahydrofuran and water, divided into four gradient inspection, the total volume of tetrahydrofuran followed by the ratio of 0%, 2.5%, 50%, 90% . Found TMPyP porphyrin would have occurred nuclear distorted , side positive charge and macrocyclicπbond formed between conjugate in the solvent-induced. The structure changes after adding acid alkali and salt,divided into three concentration gradient,0,20 mM, 100mM. Found little effect on the porphyrin after adding NaCl, Be protonated and obtained J-aggregates after adding a proton of HCl , obtained aggregates after adding NaOH ,two aggregates have different the formation mechanism.Interaction of TMPyP and ctDNA , change the molar ratio (R = [DNA] / [TMPyP]),Found the concentration of DNA not TMPyP can affect the binding mode largely. Intercalation model changes little after injecting salt ions.The above research is very important for the study of TMPyP'nature and the development for supermolecular structure,but also for the detailed study of the interaction TMPyP with DNA and other biological macromolecules .