Please wait while the transcript is being prepared...
0:00
Welcome to the talk on Mechanistic Aspects of Chaperonin GroEL/ES Function.
My name is Amnon Horovitz,
and I'm from the Weizmann Institute of Science in Israel.
0:10
Protein folding in vitro under appropriate conditions is a spontaneous process.
In other words, under the appropriate folding conditions,
unfolded molecules are able to fold into
the correct native structure either via intermediate states,
as in the case of B in the scheme on the right,
or not, as in the case of A,
since all the information required for
correct folding is contained in the amino acid sequence.
The situation in the cell is, however,
more complicated, owing to macromolecular crowding,
co-translational folding and involvement of
the molecular chaperones and folding catalysts.
0:42
Under conditions that are not optimal for folding,
such as the crowding conditions that exist in the cell,
folding yields a compromised owing to kinetic partitioning between correct folding,
information of off-pathway intermediates and the aggregates.
The role of molecular chaperones, in general,
is to prevent formation of such off-pathway intermediates or aggregates,
reverse these processes when they occur,
and enhance correct folding by smoothing the energy landscape.
In other words, also by destabilizing on-pathway intermediates.
1:15
One particular class of molecular chaperones are the chaperonins,
which are the subject of this talk.
This class has fascinated researchers because of their broad specificity.
In other words, they can assist the folding of
many unrelated proteins and their machine-like properties.
Chaperonins can be considered as machines since they use fuel in the form of
ATP to undergo coordinated motions in time and space in order to carry out work,
which, in this case, is protein folding.
