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NOTE TO JOURNALISTS: Photos are available on the Web at http://www.uh.edu/admin/media/nr/2006/05may/
050306vekilov-georgiou.html. High-resolution versions are available
by contacting Lisa Merkl.
DIABETES RESEARCH AT
UH ‘CRYSTALIZES’ WITH MAJOR FINDING
New Insulin-production Method Holds Promise for Diabetics, Impacts
Other Fields
HOUSTON, May 8, 2006 – A University of Houston professor
and his student have made a major discovery in the field of diabetes
research and diagnosis, finding a new mechanism for the formation
of insulin crystals in the pancreas.
Peter Vekilov, associate professor of chemical engineering, and
Dimitra Georgiou, a recent doctoral graduate in chemical engineering,
both in UH’s Cullen College of Engineering, are behind this
breakthrough. Since insufficient insulin production in the pancreas
is one of the manifestations of adult-onset diabetes, Vekilov and
Georgiou are studying the process of how insulin is produced in
the first place. Understanding how the body creates this hormone
will make it easier for researchers to discover why some individuals
do not produce enough insulin and thus develop diabetes, Vekilov
said. Specifically, the two have focused on the creation of insulin
crystals, the form in which insulin is stored in the pancreas before
it is released in the bloodstream.
“It is possible that the insulin deficiency happens when
the crystals don’t form properly and then part of the insulin
that is produced gets destroyed,” Vekilov said.
Proinsulin, a molecular precursor to insulin itself, is the reason
for these crystals. After an insulin molecule is produced from proinsulin,
it attaches to an insulin crystal only in special locations where
other insulin molecules have formed right angles, called kinks.
Using atomic-force microscopy, they discovered a new mechanism by
which insulin molecules attach themselves to crystals to form these
kinks. They found that groups of insulin blocks create large protrusions,
dubbed “mounds” by Vekilov and Georgiou. The very nature
of these mounds results in the creation of multiple kinks –
far more, in fact, than other methods of kink formation.
By providing so many spaces where insulin molecules can attach to
an insulin crystal, these mounds allow for the rapid growth of that
crystal and only form when there is a surplus of insulin that allows
for rapid crystal growth. Since no mounds appear when there is a
lack of insulin and insulin crystals both grow and dissolve at kinks,
mounds are important sources of a crystal’s net growth.
“Typically in nature, fast growth also results in fast dissolution,”
Vekilov said. “But this process cheats physics because when
there isn’t a lot of insulin, mounds don’t form. It’s
an asymmetric mechanism that has no balance.”
While this discovery will play a significant role in gaining a better
understanding of diabetes, it also is an historic find in the area
of crystal formation and use, as only the third mechanism of crystal
formation ever discovered. Before this finding, there were only
two known ways that crystals grew – the first was proposed
in 1876 and the second in 1968. Though the first and second discoveries,
proposed by prominent American scientist and founder of modern thermodynamics
J.W. Gibbs and by Russian scientist V.V. Voronkov, respectively,
only recently demonstrated their applicability to real systems,
this latest mechanism has already been experimentally proven in
the work by Vekilov and Georgiou.
“It is possible that crystals composed of materials other
than insulin also grow in this manner,” Vekilov said. “If
so, this discovery could significantly impact any number of fields
that deal with crystals. It can help us understand all processes
of crystal formation, including semiconductor and optical materials,
geological crystallization, ice formation and the physiological
and pathological crystallization of proteins and small molecules.”
About the University of Houston
The University of Houston, Texas’ premier metropolitan research
and teaching institution, is home to more than 40 research centers
and institutes and sponsors more than 300 partnerships with corporate,
civic and governmental entities. UH, the most diverse research university
in the country, stands at the forefront of education, research and
service with more than 35,000 students.
About the Cullen College of Engineering
UH Cullen College of Engineering has produced five U.S. astronauts,
ten members of the National Academy of Engineering, and degree programs
that have ranked in the top ten nationally. With more than 2,600
students, the college offers accredited undergraduate and graduate
degrees in biomedical, chemical, civil and environmental, electrical
and computer, industrial, and mechanical engineering. It also offers
specialized programs in aerospace, materials, petroleum engineering
and telecommunications.
To receive UH science news via e-mail, visit www.uh.edu/admin/media/sciencelist.html.
For more information about UH visit the university’s ‘Newsroom’ at www.uh.edu/admin/media/newsroom.
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