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Topic Name: The interaction between two molecules to show the basic mechanism underlying chiral recognition
Category: Polymer Interfaces and Macromolecular Assemblies
Research persons: Magalí Lingenfelder, Giulia Tomba, Giovanni Costantini, Lucio Colombi Ciacchi, Alessandro De Vita, Klaus Kern
Location: Hofgartenstraße 8,80539 Munich,Telephon: +49 (89) 2108 - 0,, Germany
Details
A human body has more than 10 to the power of
27 molecules with about one hundred thousand different shapes and functions.
Interactions between molecules determine our structure and keep us alive.
Researchers at the Max Planck Institute for Solid State Research in Stuttgart in
collaboration with scientists from the Fraunhofer Institute in Freiburg and the
King’s Collage London have followed the interaction of only two individual
molecules to show the basic mechanism underlying recognition of dipeptides. By
means of scanning tunnelling microscopy movies and theoretical simulations they
have shown how dynamic interactions induce the molecular fit needed for the
transfer of structural information to higher levels of complexity. This dynamic
picture illustrates how recognition works at the very first steps, tracking back
the path in the evolution of complex matter.If
one thinks that there are thousands of times more molecules forming our body
than stars in the universe it is astonishing how all these molecules can work
together in such an organised and efficient way. How can our muscles contract to
make us walk? How can food be metabolised every day? How can we use specific
drugs to relieve pain?
To work as a perfect machine, our body ultimately relies on the capability of
each little part (molecule) to know a specific function and location out of
countless possibilities. To do this, molecules carry information in different
ways. An international team at the Max Planck Institute for Solid State Research
in Stuttgart, in collaboration with scientists from the Fraunhofer Institute in
Freiburg and the King's College London are seeking to find out how the
information can be passed on at the very first steps: from the single molecule
level to structures of increasing complexity and functionality.
The key to understanding all biological processes is recognition. Each molecule
has a unique composition and shape that allows it to interact with other
molecules. The interactions between molecules let us - as well as bacteria,
animals, plants and other living systems - move, sense, reproduce and accomplish
the processes that keep all living creatures alive.
A very common example of recognition can be experienced in daily life whenever
one meets someone and shakes right hands. In principle, one can also shake left
hands; the fact that we do it with the right has historically been a sign of
peace, used to show that both people hold no weapon. But, have you ever attempt
to shake the right hand of a person using your left hand? No matter how the two
hands are oriented, you will never fit your left hand with the right hand of
your friend.
Many molecules can recognise each other and transfer information exactly in the
same way, they can either be "right handed" (D) or "left handed" (L). This
property called "chirality" is a spectacular way to store information: a chiral
molecule can recognise molecules that have the same chirality (same
"handedness", L to L or D to D) and discriminate the ones of different chirality
(L to D and D to L).
Probably one of the most exciting mysteries of Nature is why the building blocks
of life, i.e. amino acids (the building blocks of proteins) are exclusively
present in the chiral L form and sugars (which constitute DNA) are all in the D
form. Once more, the reason for this preference is "historical", but this time
goes back millions of years till the origins of the biological world. Scientists
believe that current life forms could not exist without the uniform chirality ("homochirality")
of these blocks, because biological processes need the efficiency in recognition
achieved with homochiral substances. In other words, the separation of molecules
by chirality was the crucial process during the Archean Era when life first
emerged.
Researchers of the Max Planck Institute for Solid State Research have now used
the "nanoscopic eye" of a scanning tunnelling microscope to make movies
following how two adsorbed molecules (diphenylalanine, the core recognition
motif of Alzheimer amyloid polypeptide) of the same chirality can form
structures (pairs, chains) while molecules of different chirality discriminate
and cannot form stable structures.
As it occurs when you shake the hand of your friend, the fact that the two
homochiral hands are complementary by shape is not enough, you both have to
dynamically adapt and adjust your hands to reach a better fit, a comfortable
situation. By a combination with theoretical simulations done at Kings College
London, the researchers have shown for the first time this dynamic mechanism of
how two molecules "shake hands" and recognise each other by mutually induced
conformational changes at the single molecule level.
We live in houses, wear clothes and read books made of chiral cellulose. Most of
the molecules that mediate the processes of life like hormones, antibodies and
receptors are chiral. Fifty of the top hundred best-selling drugs worldwide are
chiral. With this contribution to the basic mechanism of chiral recognition, the
researchers have not only tracked back to the very first steps in the evolution
of living matter but have also shed light on our understanding and control of
synthetic (man-made) materials of increasing complexity.
In Images:
1.Max Planck Institute for
Solid State Research,
2.An
STM image of individual L and D Di-phenylalanine molecules adsorbed onto Cu
(110). A human body has more than one thousand trillion trillion molecules with
about one hundred thousand different shapes and functions. The researchers have
followed the interaction between two molecules to show the basic mechanism
underlying chiral recognition.
About Researchers:
Magalí Lingenfelder
(corresponding author)
Max Planck Institute for Solid State Research, Stuttgart
Tel.: +49 711 689 1620
Fax: +49 711 689 1662
E-mail: m.lingenfelder@fkf.mpg.de
Prof. Dr. Klaus
Kern
Max Planck Institute for Solid State Research, Stuttgart
Tel.: +49 711 689 1660
Fax: +49 711 689 1662
E-mail:
k.kern@fkf.mpg.de
Dr. Giovanni Costantin
Room: 5C24
Phone: +49-711-689-1541 (Office); 1207/1415
(Lab)
Fax: +49-711-689-1602
e-mail: G.Costantini[at]fkf.mpg.de
Dr. Lucio Colombi Ciacchi
lucio@izbs.uni-karlsruhe.de
Physikalische Werkstoffmodellierung,
Fraunhofer-Institut für Werkstoffmechanik,
Freiburg
Alessandro Crociani
Max-Planck-Institut für Polymerforschung,
Ackermannweg 10,
D-55128 Mainz, Germany, Tel. +49-6131-379 248, Fax +49-6131-379 100,
email: hess@mpip-mainz.mpg.de
Funded:
An international team at the
Max Planck Institute for Solid State Research in Stuttgart, in collaboration
with scientists from the
Fraunhofer Institute in Freiburg and the
King's College
London.
Scientists and researchers from Max Planck
Institutes cooperate with their partners in Germany and abroad primarily in
fixed-term individual projects.
However, the institutes are also involved in many long-term research projects,
facilities, and programs both at home and abroad.
Max Planck Institutes have also assumed responsibility for coordinating and
managing selected national and international research programs.
If necessary for the research at its institutes, the Max Planck Society is also
active in operating and developing major equipment, research programs, computer
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