Quantum mechanical studies of bioenergetics: Photosynthesis and respiration
by
Per Siegbahn(SU, Stockholm)
→
Europe/Stockholm
Oskar Klein Auditorium
Oskar Klein Auditorium
Description
High accuracy quantum mechanical studies of functions of enzymes is a
relatively new branch of biochemistry, now about a decade old. The
method of preference has been density functional theory (DFT) in its
hybrid form, where a fraction of exact exchange is introduced. In the
present talk I will describe results obtained in the area of
bioenergetics, which by tradition includes photosynthesis and
respiration. The reactions involved in these two cases are their
opposites, formation of oxygen from water and burning of oxygen to
water, respectively. The general strategy to attack the complex enzyme
systems involved will be described. The emphasis will be on the
combination of insight and technical advancements necessary to reach
interesting conclusions, which is particularly well illustrated by the
studies on respiration. In photosynthesis a break-through for this
approach was made recently. A few years ago a prediction of both
mechanism of oxygen formation and structure of the manganese catalyst
was made based on DFT model studies. The first high-resolution X-ray
structure has just appeared (Shen et al, Nature, in press), showing
that the structure of the catalyst is nearly identical to the one
predicted by theory.
