Light-Driven Enzymatic Reaction in Thermophilic Protochlorophyllide Oxidoreductase

摘要

Within the chlorophyll biosynthetic pathway NADPH:protochlorophyllide oxidoreductase (POR; EC 1.3.1.33) catalyzes the light-dependent trans addition of hydrogen across the C17-C18 double bond of the D-ring of protochiorophyllide (Pchlide) to produce chlorophyllide (Chlide) (1). The fact that POR is light activated means the enzyme:substrate complex can be formed in the dark, removing the diffusive components out of the reaction. It was previously shown that the POR-catalyzed reaction can be observed in real time on a picosecond timescale after initiating catalysis with a 50 fs laser pulse. (2)In the present work. POR, from the thermophilic cyanobacterium The rmosvnechococcus elongatus BP-1, has been analyzed in the same way.