Metalloporphyrin mediated DNA cleavage by a low concentration of HaeIII restriction enzyme.
The plasmid DNA scission by the restriction enzyme HaeIII was investigated in the presence of tetrakis(1-methylpyridinium-4-yl)porphyrin (H2TMPyP) and its manganese(III), iron(III), nickel(II), cobalt(III) and zinc(II) derivatives. The effect of metalloporphyrins on plasmid DNA cleavage was ascertained by gel electrophoresis. UV-Vis absorption spectroscopy and circular dichroism (CD) spectroscopy. In the absence of the metalloporphyrins, plasmid DNA scission did not occur in the presence of a low concentration of HaeIII (0.2 units microL(-1)) at 37 degrees C after 1 h incubation. However, DNA cleavage occurred in the presence of the metalloporphyrins and HaeIII (0.2 units microL(-1)) at 37 degrees C after 1 h incubation. Gel electrophoresis results indicate the catalytic effect of metalloporphyrins (Mn(III)-, Fe(III)-, Co(III)- and Zn(II)TMPyP) by binding to both DNA and the enzyme through electrostatic interaction, which was confirmed by the change in UV-Vis and CD spectra. A mechanism for the enhanced DNA cleavage is proposed.
Tabata
M
M
Department of Chemistry, Faculty of Science and Engineering, Saga University, Japan. tabatam@cc.saga-u.ac.jp
Nakajima
K
K
Nyarko
E
E
D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism*; D004587:Electrophoresis, Agar Gel; D008665:Metalloporphyrins / Q000378:metabolism*; D008956:Models, Chemical; D010957:Plasmids / Q000378:metabolism; D013053:Spectrophotometry; D014466:Ultraviolet Rays
D008665:Metalloporphyrins; D004247:DNA; D015252:Deoxyribonucleases, Type II Site-Specific; C024403:GGCC-specific type II deoxyribonucleases