0000000000384448
AUTHOR
G. Panek
Localization of the N-terminal Domain in Light-harvesting Chlorophyll a/b Protein by EPR Measurements
The conformational distribution of the N-terminal domain of the major light-harvesting chlorophyll a/b protein (LHCIIb) has been characterized by electron-electron double resonance yielding distances between spin labels placed in various domains of the protein. Distance distributions involving residue 3 near the N terminus turned out to be bimodal, revealing that this domain, which is involved in regulatory functions such as balancing the energy flow through photosystems (PS) I and II, exists in at least two conformational states. Models of the conformational sub-ensembles were generated on the basis of experimental distance restraints from measurements on LHCIIb monomers and then checked f…
Data analysis procedures for pulse ELDOR measurements of broad distance distributions
The reliability of procedures for extracting the distance distribution between spins from the dipolar evolution function is studied with particular emphasis on broad distributions. A new numerically stable procedure for fitting distance distributions with polynomial interpolation between sampling points is introduced and compared to Tikhonov regularization in the dipolar frequency and distance domains and to approximate Pake transformation. Distance distributions with only narrow peaks are most reliably extracted by distance-domain Tikhonov regularization, while frequency-domain Tikhonov regularization is favorable for distributions with only broad peaks. For the quantification of distribut…