FACTORS INFLUENCING THE STABILITY OF ATP IN TERNARY COMPLEXES - SPECTROSCOPIC INVESTIGATION OF THE INTERACTION OF CERTAIN BIOMIMETIC COPPER(II) COMPLEXES WITH ATP AND AMP
I. Somasundaram et M. Palaniandavar, FACTORS INFLUENCING THE STABILITY OF ATP IN TERNARY COMPLEXES - SPECTROSCOPIC INVESTIGATION OF THE INTERACTION OF CERTAIN BIOMIMETIC COPPER(II) COMPLEXES WITH ATP AND AMP, Journal of inorganic biochemistry, 53(2), 1994, pp. 95-107
The interaction of Cu(salgly)(H2O) (1), Cu(sal-alpha-ala)(H2O) (2), Na
(salglygly)Cu(II) (3), Cu(glygly)(H2O) (4), [Cu(salen)(H2O)](ClO4) (5)
, [Cu(sal-N-Meen)](ClO4)(6), and [Cu(sal-N,N-Me(2)en)(H2O)](ClO4)(7) w
ith ATP and AMP has been studied using FTIR, ligand field and EPR spec
troscopy, and H NMR line-broadening techniques. These complexes intera
ct equatorially with ATP through the phosphate group and with AMP thro
ugh N(7), forming 1:1 species and stabilizes it from dephosphorylation
. The extent of interaction of the complexes with ATP decreases in the
order 1 greater than or equal to 2 > 7 > 3 greater than or equal to 4
. EPR studies also indicate the formation of ternary species involving
the gamma-phosphate group of ATP and N(7) of AMP. However, the prefer
ential broadening of H(8) resonance for all the complexes indicates th
e binding of ATP through N(7) of the purine base moiety and possibly t
hrough phosphate also. ATP was found to be dephosphorylated by [Cu(sal
en)(H2O)](+) and [Cu(sal-N-Meen)](+) complexes. Our observations indic
ate that the primary amino group having the potential to form hydrogen
bonds with ATP coupled with the positive charge on the chelate in add
ition to N(7) coordination may facilitate dephosphorylation.