REACTIVITY OF CHLOROPHYLL db-PROTEINS AND MICELLAR TRITON X-100 COMPLEXES OF CHLOROPHYLLS a OR b WITH BOROHYDRIDE
نویسندگان
چکیده
The reaction of several plant chlorophyll-protein complexes with NaBH, has been studied by absorption spectroscopy. In all the complexes studied, chlorophyll b is more reactive than Chl a , due to preferential reaction of its formyl substituent at C-7. The complexes also show large variations in reactivity towards NaBH, and the order of reactivity is: LHCI > PSI1 complex > LHCII > PSI > P700 (investigated as a component of PSI). Differential pools of the same type of chlorophyll have been observed in several complexes. Parallel work was undertaken on the reactivity of micellar complexes of chlorophyll a and of chlorophyll b with NaBH, to study the effect of aggregation state on this reactivity. In these complexes, both chlorophyll a and b show large variations in reactivity in the order monomer > oligomer > polymer with chlorophyll b generally being more reactive than chlorophyll a. It is concluded that aggregation decreases the reactivity of chlorophylls towards NaBH, in vitro, and may similarly decrease reactivity in naturally-occurring chlorophyll-protein complexes.
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