Domain movement in rabbit muscle adenylate kinase might involve proline isomerization.
The fluorescence probe, 8-anilino-1-naphthalenesulfonic acid (ANS), was used to monitor the induced-fit conformational movement in rabbit muscle adenylate kinase. In 50 mM Tris-HCl buffer (pH 8.1), the time course of ANS binding to rabbit muscle adenylate kinase is a biphasic process. The fast phase completes within the dead-time of the stopped-flow equipment used (about 15 ms), while the slow phase ends in about 10 minutes. In the presence of 2.0 microM peptidyl prolyl cis/trans-isomerase, the rate constant of the slow phase reaction is accelerated about 2.4-fold, suggesting that the domain movement during ANS binding to rabbit muscle adenylate kinase may involve proline isomerization. The activation energy of the slow phase was determined to be 74.6 kJ/mol, which is comparable to the activation energy of proline cis/trans-isomerization (about 80 kJ/mol).
Sheng
X R
XR
National Laboratory of Biomacromolecules, Institute of Biophysics, Academia Sinica Beijing, China.
Zhang
H J
HJ
Pan
X M
XM
Li
X F
XF
Zhou
J M
JM
D000263:Adenylate Kinase / Q000737:chemistry* / Q000378:metabolism; D000591:Amino Acid Isomerases; D000817:Anilino Naphthalenesulfonates; D000818:Animals; D001665:Binding Sites; D002151:Calorimetry; D002352:Carrier Proteins; D002384:Catalysis; D004789:Enzyme Activation; D005456:Fluorescent Dyes; D007700:Kinetics; D018482:Muscle, Skeletal / Q000201:enzymology*; D019696:Peptidylprolyl Isomerase; D011392:Proline; D011487:Protein Conformation; D011817:Rabbits; D013237:Stereoisomerism; D013816:Thermodynamics
D000817:Anilino Naphthalenesulfonates; D002352:Carrier Proteins; D005456:Fluorescent Dyes; C027132:1-anilino-8-naphthalenesulfonate; D011392:Proline; D000263:Adenylate Kinase; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase