[Analysis of ESR spectra in Mn2+-plant adenylate kinase complex]

Interaction of plant adenylate kinase with Mn2+-adenine nucleotide binary complex was studied by ESR technique at room temperature. The ligand environment of Mn2+ in the ternary Mn2+-adenine nucleotide-enzyme complex was shown to change, as a result of enzyme binding as compared with that of binary complex. These changes seem to be due to substitution of protein molecules for water and adenine nucleotide ones, coordinated to Mn2+ ion on ternary complex formation. The same results were obtained in ESR studies on rabbit muscle myokinase. This fact may be considered as an evidence, that plant adenylate kinase is identical to animal one in its interaction with adenine nucleotides and manganese ions.