The binding of ATP and AMP to Escherichia coli adenylate kinase investigated by 1H and 15N NMR spectroscopy.
[N6 15N]ATP and [N6 15N]AMP, complexed with E.coli adenylate kinase (AKe), were observed with 15N isotope-filtered NMR pulse sequences and 1H[15N] heterocorrelated experiments to determine differences between binding sites based on chemical shifts and competition by substrate analogs. The chemical shifts of the N6 amino proton and nitrogen signals changed significantly after mixing with adenylate kinase. Differences in chemical shifts between the bound ATP and AMP signals are slight. The response of these shifts to further addition of other substrates or Mg2+ supports the view that the unchelated nucleotides can bind to both the sites, whereas the metal complexed species are restricted to the MgATP/MgADP binding site.
Glushka
J
J
Rockefeller University, N.Y., N.Y. 10021.
Bârzu
O
O
Sarfati
R S
RS
Kansal
V K
VK
Cowburn
D
D
D000249:Adenosine Monophosphate / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000378:metabolism*; D000263:Adenylate Kinase / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009584:Nitrogen; D011485:Protein Binding
D000249:Adenosine Monophosphate; D006859:Hydrogen; D000255:Adenosine Triphosphate; D000263:Adenylate Kinase; D009584:Nitrogen