Folding of molecular biology. Universidad Pontificia Bolivariana. Facultad de Medicina. Tercer semestre 2014-01

1. Researchers use DNA strands to build
decomposable nanostructures and where
does the pathological misfolding of the
prion originate?
Laura Arango Gutiérrez
Medical Student

2. FOLDING

3. FOLDING

4. A clear example of what I want to
explain is cancer because of its
characteristic excess in cell growth due
to damages in the control mechanisms
of the cell during its cycle.
For that reason , cancer treatments are
designed to affect DNA, RNA and
proteins so as to stop the pathological
process of the cell cycle

5. Some years researchers found
the use of nanostructures
build from nanoparticles as a
method to deliver drug
directly to the tumor, killing it

6. Researchers use DNA strands to
build decomposable nanostructures
But there was a problem: the
materials of nanostructures
are considered toxic if they
build up in the body and the
structures are too big for the
body so it’s difficult to break
down and to remove them.

7. Researchers use DNA strands to
build decomposable nanostructures
Nanoparticles
DNA strands
The use of DNA strands to tie nanoparticles and
polymers can mediate the assembly of larger
nanostructures and control their interactions
with biological systems.
Nanoparticles tie with
DNA strands form
Nanostructures

8. Researchers use DNA strands to
build decomposable nanostructures
The researchers tested
in mice and they found
that nanoparticles were
in mouse urine,
indicating that the mice
system were able to
remove the smaller
sized nanostructures

9. Student Observation
I think the knowledges on
the subject should be
extended, thus this method
could be use in people
because the use of friendly
nanostructures with the
body results a good strategy
for the treatment of cancer
because it decreases the
secondary effects of the
cancer drugs. It implies to
improve the quality life of
patients which is a clear
objective of all scientific
advances

10. The investigation was based
on the idea that when prions
are healthy they look like tiny
spheres but when they are
malignant they look like
cubes

11. Where does the pathological misfolding
of the prion originate?
“Prions are unique infective agents –unlike viruses, bacteria,
fungi and other parasites, prions do not contain either DNA or
RNA”
In fact, prions are one of the exceptions of the central dogma of
molecular biology because they are proteins able to infect.

12. Where does the pathological misfolding
of the prion originate?
The pathological effects
of the malignant proteins
can propagate quickly
because
PrPSc
(the
pathological form of the
prion protein) can induce
to PrPc (normal prions
protein) to change its
conformation
and
convert it in diseasecausing agents.

13. Where does the pathological misfolding
of the prion originate?
To know the place where the
pathological misfolding of the
prion originate, researchers use Xrays, synthetic prion proteins and
small proteins (nanobodies) that
were used like plataforms and they
induce prions to stabilize their
structure.
With this, they found that the early prion pathological
misfolding occurs in the N-terminal subunit.

14. Student Observation
I think that this kind of
investigation represents a
major step in the sciencie
because keep researching
about the way how the prions
are modified to convert into
disease-causing agents and
find results on this topic
means find therapeuctic
stretagies against incurable
neurodegenerative diseases.
This investigation is an
example of the importance of
the molecular approach in the
study of the pathologies

15. It is very important to know
the molecular basis of the
different pathologies to find a
treatment that makes its
effect on the molecular
proccess of the cells involve in
diseases

16. Medical utility
The use of decomposable
nanostructures tie with DNA
strands could be a very
useful method in the
treatment of cancer, for
example in chemotherapies

17. Medical utility
Nanostructures act directly on
the tumor cells decreasing the
secondary effects of these
treatments.
This is very important because
the objective of scientific
advances is to improve and
impact positively on people's
lives and this research may
mean an improvement in the
quality of life of patients with
cancer.

18. Medical utility
Considering that prions are
misfolded proteins that
cause a group of incurable
neurodegenerative
diseases like spongiform
encephalopathies, the fact
of knowing the place
where the pathological
misfolding of the prion
originate will allow to
create a possible cure and
treatment
for
neurodegenerative
diseases
Spongiform encephalopathy: Mad cow disease

19. Bibliography

CHOU, L; ZAGOROVSKY, K; CHAN, W (2014, January 26) DNA assembly of
nanoparticle superstructures for controlled biological delivery and
elimination. Nature Nanotechnology (2014) Retrieved February 7, 2014
from
http://phys.org/news/2014-01-dna-strands-decomposablenanostructures.html

ABSKHARON N. N., R; GIACHIN, G; Wohlkonig, A; SOROR, S; PARDON, E.;
LEGNAME, G., et all."Probing the N-Terminal β-Sheet Conversion in the
Crystal Structure of the Human Prion Protein Bound to a Nanobody.",
Journal of the American Chemical Society 2014 136 (3), 937-944. Retrieved
February 7, 2014 from http://phys.org/news/2014-01-pathologicalmisfolding-prion.html#jCp

MARTINEZ SÁNCHEZ, Lina María. Biología molecular. 7. ed. Medellín:
UPB. Fac. de Medicina, 2012. 74-77 p.