MOLECULAR CHAPERONES

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The Department of Biochemistry of Medical Faculty
Presents now
MOLECULAR CHAPERONES
Edited by Attila Sandor
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three dimensional information
one dimensional information
L. Fig.3-16, p.89
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The model proteins for classic study of
developing the three dimensional structure, that
for folding. (Anfinsen)
Str., Fig. 7.1, p.172
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Str. Fig. 3.53, p. 65
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Scrambled
Str. Fig. 3.54, p. 66
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The three dimensional structure is dictated
entirely by the amino acid sequence
Str., Fig1.6 p.7
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Free energy
L.Fig.4-29,p. 149
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Str. Fig. 3.57, p. 68
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Role of chaperones in the thermodynamic point of
view

1. The folding of the unfolded protein (U) to the
   correct (C) form is favored thermodynamically.
   Chaperone is not necessary.
2. The folding of the unfolded protein (U) to the
   incorrect (I) form is favored thermodynamically.
   Chaperone is necessary.

Ellis R.J., Annu. Rev. Biochem., 1991
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The idea of molecular chaperones
Named after the human chaperone usually an
elderly woman who accompanies a young unmarried
lady to prevent not proper interactions with
other people.
Molecular chaperones proteins assisting folding
of nascent polypeptides, by preventing wrong
folding.
Molecular chaperones catalyze the formation of
correctly folded, functionally active, native
proteins, but they are not part of the product.
Expression of many chaperon is induced by stress,
such as by heat, because during heat-stress the
probability of wrong folding is higher, therefore
cells need more protection. These chaperons are
called heat shock proteins (HSPs).
Authors slide
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Representative members of the Chaperone family
Heat shock proteins 70 ( Hsp70)
Nucleoplasmins
Nucloplasmin NucleoplasminS
Chaperonins
Heat shock proteins 90 (Hsp90)
chaperonin 60, groEL chaperonin 60,
groELchaperonin 10, groES (mitochondrial,
bacterial) may use ATP
Ellis R.J., Annu. Rev. Biochem., 1991
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Role of nucleoplasmines assably of chromatin
DNA Histone
aggregate
DNA Nucleoplasmin Histone
Nucleosoma (DNA Histone)
Nucleoplasmin
Authors picture
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Representative members of the Chaperone family
Heat shock proteins 70 ( Hsp70)
Nucleoplasmins
Nucloplasmin NucleoplasminS
Chaperonins
Heat shock proteins 90 (Hsp90)
chaperonin 60, groEL chaperonin 60,
groELchaperonin 10, groES (mitochondrial,
bacterial) may use ATP
Ellis R.J., Annu. Rev. Biochem., 1991
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RUBISCO and the chaperonins
When removing guanine
very poor recovery
Rubisco denaturated with guanine at 25o C
good recovery
Rubisco denaturated with guanine at 10o C
Rubisco denaturated with guanine at 25o Cand
chaperonin 60, chaperonin 10, ATP, Mg were
added
80 recovery
Rubisco ribulose 1,5-bisphosphate
carboxylase-oxygenase
Authors slide
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L.Fig.41-31, p.152
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THANK YOU FOR YOUR ATTENTION
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c\sandor\chaperon.ppt
Attila Sandor