NUCLEASE-LIKE ACTIVITY OF A CYCLIC TETRAMERIC SCHIFF-BASE (TETRAANHYDROAMINOBENZALDEHYDE) N-COORDINATED COPPER COMPLEX

Chemical nucleases are compounds that are able to bind to the surface of nucleic acids and are involved in the generation of free radicals w hich cleave nucleic acids. The aim of this study was to investigate th e interaction of copper(II) tetrabenzo [b,f,j,n] [1,3,9,13] tetraazacy clohexadecine (Cu(TAAB)(2+)) with DNA and determine the DNase-like act ivity of this complex. Dichroic properties, electronic absorption and electrophoretical techniques were used to study the reaction of the co mplex with DNA. Cu(TAAB)(2+) affected the dichroic properties and u.v. absorption of calf thymus DNA under anaerobic conditions. The anaerob ic melting point of DNA was not affected in the presence of Cu(TAAB)(2 +). The hyperchromicity of DNA at 260 mn in the presence of Cu(TAAB)2 with both ascorbic acid and oxygen was determined and compared with t he known chemical nuclease Cu(phenantroline)(2). Plasmid DNA in the pr esence of ascorbic acid and oxygen was effectively cleaved by Cu(TAAB) (2+) in a concentration dependent manner. It is concluded that the Cu( TAAB)(2+) complex is a potential chemical nuclease.