1996 Fiscal Year Final Research Report Summary
STUDY OF HYDROLYTIC ACTIVITIES OF THREE COMPONENT COMPLEXES OF DNA・LIGANDS・METAL ION
| Project/Area Number |
07680635
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Bioorganic chemistry
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| Research Institution | OSAKA CITY UNIVERSITY |
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Principal Investigator |
OGINO Kenji OSAKA CITY UNIVERSITY,DEPT.BIOAPPLIED CHEMISTRY,PROFESSOR, 工学部, 教授 (30089958)
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| Project Period (FY) |
1995 – 1996
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| Keywords | PLASMIDE DNA / HYDROLYSIS / METAL ION COMPLEX / RESTRICTION ENZYME MODEL |
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| Research Abstract |
Metal ion effects on the phosphoryl and nucleotidyl hydrolyses and transfer reactions have been a long lasting subject of broad interests. We studied the site-selective hydrolyses of UTPs (ATP and UTP) promoted by metallo-complexes of appropriate ligands. The ligands (L) synthesized and examined were 2,2'-dipyridylamine (dpa) derivatives in which dpa is linked to adenine, thymine, and guanine mojities with a methylene-spacer of different lengths.
The hydrolyses of ATP and UTP were carried out at pH 7.3 and 40ﾟC for 24 h and the amounts of the hydrolyses (NDP and NMP) were monitored by an anion-exchange HPLC.The 1 : 1 stoichiometric complexes of Cu(L)^<2+>, adenine containing ligand, were found to be superior in both the activities (hydrolyses %) and site-selectivities (ratios of ADP/AMP and UDP/UMP) as compared to other divalent metal ions (Cu^<2+>, Mg^<2+>, Zn^<2+> and Ni^<2+>) alone or their M (L) ^<2+>-complexes. The Cu(L)^<2+>-complexes showed the preferential cleavages of the terminal gamma-phosphate groups, although Cu(dpa)^<2+>, the active site of these ligands, inhibited their hydrolyses. The effect of reactivities of these complexes and their spacer-lengths suggests the interactions of the base-base moieties between ATP or UTP and the ligands. The formation of the ternary complex of Zn^<2+> : L : ATP was studies by using ^1H-and ^<31>P- NMR spectra. The hydrolytic activities of other ligands are investigated now.
As DNA cleaving reagents, these M^<2+>-ligand complexes were examined to investigate their reactivities for thecleavages of plasmide DNA (pCU 18) and the Zn(L)^<2+> complexes, ademine containing ligand, were found to be effective (supercoil plasmide DNA (Form I) hydrolyzed to nicked (Form II) and linear DNA (Form III), measured after electrophyrisis) and indicated to work as a kind of models of distriction enzymes.
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