Proton-nuclear magnetic resonance studies of the aromatic spin systems of Escherichia coli adenylate kinase.
Escherichia coli adenylate kinase has a very well resolved proton nuclear magnetic resonance spectrum in the region containing signals from aromatic amino acid side-chains. We found that the protein is structurally stable over a wide pH range and renatures spontaneously after acidic as well as basic denaturation. Only one out of the three histidyl imidazole rings titrates on changing the pH and has a pka value of 7.6. Two-dimensional nuclear magnetic resonance spectroscopy studies allowed use to identify most of the enzyme's aromatic spin systems, and by investigation of a mutant protein we were able to assign the aromatic part of the spin system of Tyr24 unambiguously.
Bock
I
I
Max-Planck-Institute for Medical Research, Dept. of Biophysics, Heidelberg, Germany.
Reinstein
J
J
Brune
M
M
Wittinghofer
A
A
Rösch
P
P
D000263:Adenylate Kinase; D004926:Escherichia coli / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D010770:Phosphotransferases; D011522:Protons
D011522:Protons; D010770:Phosphotransferases; D000263:Adenylate Kinase