TY - JOUR
T1 - Backbone dynamics of plastocyanin in both oxidation states
T2 - Solution structure of the reduced form and comparison with the oxidized state
AU - Bertini, Ivano
AU - Bryant, Donald A.
AU - Ciurli, Stefano
AU - Dikiy, Alexander
AU - Fernández, Claudio O.
AU - Luchinat, Claudio
AU - Safarov, Niyaz
AU - Vila, Alejandro J.
AU - Zhao, Jindong
PY - 2001/12/14
Y1 - 2001/12/14
N2 - A model-free analysis based on 15N R1, 15N R2, and 15N-1H nuclear Overhauser effects was performed on reduced (diamagnetic) and oxidized (paramagnetic) forms of plastocyanin from Synechocystis sp. PCC6803. The protein backbone is rigid, displaying a small degree of mobility in the sub-nanosecond time scale. The loops surrounding the copper ion, involved in physiological electron transfer, feature a higher extent of flexibility in the longer time scale in both redox states, as measured from D2O exchange of amide protons and from NH-H2O saturation transfer experiments. In contrast to the situation for other electron transfer proteins, no significant difference in the dynamic properties is found between the two redox forms. A solution structure was also determined for the reduced plastocyanin and compared with the solution structure of the oxidized form in order to assess possible structural changes related to the copper ion redox state. Within the attained resolution, the structure of the reduced plastocyanin is indistinguishable from that of the oxidized form, even though small chemical shift differences are observed. The present characterization provides information on both the structural and dynamic behavior of blue copper proteins in solution that is useful to understand further the role(s) of protein dynamics in electron transfer processes.
AB - A model-free analysis based on 15N R1, 15N R2, and 15N-1H nuclear Overhauser effects was performed on reduced (diamagnetic) and oxidized (paramagnetic) forms of plastocyanin from Synechocystis sp. PCC6803. The protein backbone is rigid, displaying a small degree of mobility in the sub-nanosecond time scale. The loops surrounding the copper ion, involved in physiological electron transfer, feature a higher extent of flexibility in the longer time scale in both redox states, as measured from D2O exchange of amide protons and from NH-H2O saturation transfer experiments. In contrast to the situation for other electron transfer proteins, no significant difference in the dynamic properties is found between the two redox forms. A solution structure was also determined for the reduced plastocyanin and compared with the solution structure of the oxidized form in order to assess possible structural changes related to the copper ion redox state. Within the attained resolution, the structure of the reduced plastocyanin is indistinguishable from that of the oxidized form, even though small chemical shift differences are observed. The present characterization provides information on both the structural and dynamic behavior of blue copper proteins in solution that is useful to understand further the role(s) of protein dynamics in electron transfer processes.
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U2 - 10.1074/jbc.M100304200
DO - 10.1074/jbc.M100304200
M3 - Article
C2 - 11509552
AN - SCOPUS:0035861754
SN - 0021-9258
VL - 276
SP - 47217
EP - 47226
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 50
ER -