BIOPHYSICAL SOCIETY NEWSLETTER
12
AUGUST
2014
Know the Editors
Fazly Ataullakhanov
National Research Center for
Hematology
Moscow, Russia
Editor in Molecular Machine,
Motors and Nanoscale
Biophysics Section
What is your area of research?
My research focuses on the dynamics of biologi-
cal systems. I have worked on a broad spectrum
of projects including enzymatic reactions, such
as the peroxidase-oxidase system, and complex
metabolic pathways: their hierarchy, overall
integration, and impact on cell physiology. I also
study spatiotemporal dynamics of blood clotting
system and mechanisms of chromosome segrega-
tion during cell division. The goal of these differ-
ent studies has been to define the basic principles
and mechanisms of self-organization of complex
biological systems to understand how they func-
tion efficiently and intelligently. Work toward
this goal has required the tandem use of theoreti-
cal and experimental approaches, while seeking
a consistency between mathematical models and
experimental results. Progress in these directions
cannot be achieved working alone, and I was for-
tunate to have excellent colleagues and talented
students. Two ongoing projects are described
below.
Spatio-temporal dynamics of blood clotting.
We have constructed different mathematical
models of blood clotting pathways and developed
novel experimental approaches to monitor and
analyze the clotting reactions with high spatial
and temporal resolution. This work has estab-
lished that the propagation of clotting abides by
the same laws as the propagation of
excitation in
neurons or of the front of a flame. However, in
contrast to these well-studied excitation waves,
the clotting waves can stop. This discovery has led
to new thoughts about the pathway of blood clot-
ting in general. Apparently, different blocks of the
clotting reactions are responsible for different as-
pects of clotting: the activation, propagation, and
termination. For example, the intrinsic pathway
of blood clotting has previously been viewed as a
“metabolic atavism,” which plays no significant
role in humans. Our work has revealed that the
reactions of the intrinsic pathway are critical for
the propagation of clotting in space. These results
have also stimulated interest in the new type of
active medium, represented by blood, which we
call “double active.” Such an excitation medium
can give rise to very unusual mechanisms of
self-organization, which are likely to be involved
in other biological phenomena, including cell dif-
ferentiation and pattern formation.
Mechanisms of chromosome segregation.
One of the most crucial steps in cell division,
equal segregation of duplicated chromosomes,
is carried out by the mitotic spindle. A primary
spindle component is tubulin, which polymer-
izes to form dynamic microtubules. We have
developed novel mathematical models to study
the mechanics and dynamics of tubulin polymers,
leading to the quantitative prediction and then
experimental confirmation of the force generated
by tubulin disassembly. Shortening microtubules
can generate force that is sufficiently large to
explain poleward chromosome motion in cells,
but capturing this large force requires specialized
coupling mechanisms. We are now investigating
the operation of different protein complexes with
the goal of attaching a chromosome to the tips of
the disassembling microtubules.
Biophysical Journal Corner
