[Effect of secondary structure on the rate dark reduction of P700+ with ascorbate of the photosystem I complex].
Relationship was studied between the spectra of KD, absorption and fluorescence and kinetics of P700+ dark reduction with exogenous donor and sodium dodecyl concentration inducing a conformation transition of the protein globule. It has been shown that with a decrease of the detergent concentration from 0.01 to 0.06% an increase of the portion of the protein globule-helical regions (from 10 to 30%) and an essential decrease of the time of P700+ dark reduction with ascorbate take place. The changes of KD, absorption and fluorescence spectra of chlorophyll a observed in the same region of detergent concentration do not correlate with the changes of the secondary structure of the protein part of the pigment-protein complex. It is suggested that accelerated reduction of P700+ with ascorbate is conditioned by an increase of accessibility of exogenous donor to the reaction centre resulting from conformation changes of the complex protein part.
D001205:Ascorbic Acid; D002734:Chlorophyll / Q000378:metabolism*; D003624:Darkness; D007700:Kinetics; D010788:Photosynthesis; D010944:Plants / Q000378:metabolism; D011487:Protein Conformation; D013053:Spectrophotometry
D002734:Chlorophyll; C001785:chlorophyll P 700; D001205:Ascorbic Acid
Vliianie vtorichnoĭ struktury na skorost' temnovogo vosstanovleniia P700+ askorbatom kompleksa fotosistemy I.