Copper(II) complex formation equilibria involving L-carnosine. The role inthe catalysis of amino acid ester hydrolysis

The binary and ternary complexes of copper(II) involving carnosine (H3L), a mino acids and DNA constituents were examined. Copper(II) was found to form Cut and CuLH-1 complexes with carnosine. The ternary complexes of Copper(I I) with carnosine and DNA constituents are formed in a stepwise mechanism, whereby carnosine binds to copper(II), then followed by ligation of the DNA constituents. The concentration distribution of the various complex specie s has been evaluated. The hydrolysis of amino acid ester is catalysed by th e Cu-carnosine complex. The rate enhancement compared with the free ester h ydrolysis is investigated in terms of the ester coordination mode.