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DR. FRANK ROBB - University of Maryland, Center of Marine Biotechnology (COMB)
The Research: Biotech Applications Based on Marine Thermophiles
It may seem strange to anyone who has boiled water to make it safe, or even been scalded by the stuff, but there are
organisms known as thermophiles and hyperthermophiles that can survive and even thrive at temperatures up to 100°C (212°F),
which in mere seconds can destroy DNA, "normal" proteins, and, hence, life. Dr. Frank Robb's main interest is learning the
details of how they do it, specifically how these organisms can maintain stable proteins in the face of a thermal
onslaught. His key focus is on the proteins, known as chaperones, that the organisms produce to allow them to fold the
proteins necessary for life.
Robb and his colleagues are working toward various applications including using chaperones to improve high-temperature
industrial or biomedical processes. The team is also exploring methods that would employ chaperones for increasing
the stability of certain vaccines, increasing the chances of getting them to remote parts of the world while still usable.
A final area of research is in tapping the thermophiles' penchant for producing hydrogen as a byproduct in order to
develop new hydrogen production methods as a possible future energy source.
The search for thermophiles has taken Robb to some exotic locales, including deep-sea hydrothermal vents, geothermal
springs in the volcanic area's of Eastern Russia's Kamchatka, and Yellowstone National Park.
 - VIDEO CLIP 1: "Hot For Hyperthermophiles"
 Chaperones For When Things Get Too Hot
Proteins are essential to life, and proper folding of those proteins is essential to their utility. But the folding process, as well as the
proteins themselves, normally breaks down when temperatures reach the range where thermophiles and hyperthermophiles are found, such as
hydrothermal vents and hot springs.
Enter the chaperones. Chaperones are proteins that associate with other proteins to, as Robb puts it and the name implies, "keep them out of
trouble." More specifically, chaperones interact with proteins through various chemically charged interactions to guide how they fold, a
crucial job, as misfolded proteins cannot perform their intended functions.
Chaperones come in myriad forms and help all organisms with protein folding, not just those trying to do it at high temperatures. Chaperones
can help with initial folding of a protein or with refolding proteins that are denatured, or damaged, because of heat. The chaperones that
handle high temperature problems are different from those found in a cell under normal conditions, and by necessity they are stable at
temperatures well beyond those tolerated by the proteins they protect. Often Chaperones are not even produced by a cell until it is stressed, and so
are often referred to as heat shock proteins. Interestingly, Robb's group has found that at high temperatures there are fewer chaperones,
but they are more versatile, functioning over a wider range of temperatures.
- VIDEO CLIP 2: "Chaperoning Molecules: Keeping Proteins Out of Trouble"
Which Came First, the Chicken or the Chaperone?
Understanding that chaperones are proteins that help other proteins fold properly under conditions where it would otherwise be impossible
begs the question: how does a chaperone manage to fold itself in the first place? Robb says it's likely that there are chaperones to
chaperone the chaperones, hard as that may be to follow. Answering the question of which came first, the chaperone or the chaperone chaperone
may be a ways off, but Robb's group has made progress on the conundrum through microarray studies. They have found that a number of as yet
unidentified proteins are formed in thermophiles in response to heat shock, and these may in fact be the ones with the function of
chaperoning the chaperones.
- VIDEO CLIP 3: "Applications Utilizing Chaperoning Molecules"
The Furious Pyro
Much of Robb's research focuses on a hyperthermophile first isolated by Italian scientists, which grows in shallow water on the beach of a
volcanic Italian island. Dubbed Pyrococcus furiosus, this bacterium actually thrives at 100°C (212°F). It has been used in almost all of
Robb's protein stability studies, either by itself or in comparisons with closely related strains that grow at lower temperatures. It has
also been the target of numerous other groups looking at high-temperature adaptations of the thermophiles. Numerous other Pyrococcus species
have been discovered at deep-sea hydrothermal vents around the world, but none has been studied as closely as P. furiosus.
The Robb Lab has also isolated and described four new thermophilic species, two of which are in new genera, and there are many more
undescribed species in the lab, Robb says, which have not yet been formally described. Though he does not view such systematics work as a
main focus of the lab, he does feel it is important to culture and describe new species so that they can be used. The team is currently
collaborating with the Rockville, Maryland-based Institute for Institute for Genomic Research to genetically sequence new species, primarily to establish
genetic sequence information for the currently blank areas of the bacterial tree of life.
- VIDEO CLIP 4: "Isolating Novel Species, Genome Sequencing, and [i]Pyrococcus furiosis[/i]"
Expanding Vaccine Range Into Remote Areas
One promising potential application for Robb's chaperone research is in increasing the stability of vaccines to make them easier to deliver
to remote parts of the world. Many vaccines contain weak versions of the disease-causing agent they are used to inoculate against, and these
live organisms can be rather delicate, requiring refrigeration. Though they have not yet stabilized a particular vaccine, Robb's team has
experimental results already that suggest it may be possible to add chaperones to vaccines that would stabilize them enough to avoid or
reduce the need for refrigeration, which could significantly increase the areas in undeveloped countries that could be reached. Chaperones
may be used to either prevent the breakdown of proteins in the living cells found in certain vaccines, or of the proteins in vaccine
additives known as adjuvants that are necessary for making a vaccine effective. Two examples of vaccines that might be improved through such
research are those for typhoid and cholera.
New Hydrogen Source?
Hydrogen remains the greatest hope as a future replacement for fossil fuels, but a key hurdle to its widespread use are the limitations of
currently available sustainable hydrogen production methods. In time, though, thermophiles may offer a solution because many happen to
produce hydrogen as an end product.
Robb and his team are currently studying some organisms that take up carbon monoxide and convert
it into carbon dioxide using the oxygen in water and leaving the hydrogen. This is a particularly attractive habit, because it means that
carbon monoxide is both the energy source and the carbon source, so the organisms need nothing else to thrive and produce hydrogen. The group
has already sequenced the genome on one of these organisms and is working to identify the enzymes responsible for the hydrogen production,
known as hydrogenases. The team is also experimenting to learn if they can produce hydrogen from other substrates besides carbon monoxide.
The organisms in question typically produce hydrogen in the 60°C to 80°C range, which could be a disadvantage because reaching those
temperatures requires significant energy expenditure. But there are also has some advantages. Working at such temperatures, contamination is
unlikely, and the organisms are much easier to study because they are robust and easily isolated, given that most other organisms die off at
high temperatures. In comparison, studying enzymes involved in hydrogen production has been hampered in research with organisms from more
common, lower,temperature ranges because they can fall apart easily, hindering study of their hydrogenases.
Beyond hydrogen, Robb also envisions a broad range of additional industrial applications for chaperone and thermophile research. For
instance, E. coli is commonly modified to produce proteins needed for medical and other purposes, sometimes at industrial scales. But
attempts to induce such production often fail because of protein folding problems that might be solved with the addition of new chaperones.
The chaperones can also increase the solubility of produced proteins, increasing production potential. Finally, by extending the temperature
tolerance range for E. coli, widely used in a variety of applications, heat-shock chaperones could also simplify industrial processes where
hot spots in large reactors can shock the bacteria, halting their production of needed proteins. Increased temperature range could also have
benefits for researchers using PCR techniques.
- VIDEO CLIP 5: "Vaccines, Protein Folding, Bacteria
Farms, Hydrogen-Producing Microbes"
Educational Background
Robb attended a rural boarding school in South Africa early on and was always interested in science, though he says it was not a big part of
the curriculum at his school. Halfway through a zoology degree program at the University of Cape Town, he became interested in microbes,
though little microbiology, and no microbial genetics was taught there. So, he moved to the University of Calif., Riverside for graduate
school, to focus on these topics. There he worked on metabolic engineering at a level he now calls "primitive" before returning to South
Africa. He joined the University of Maryland's Center of Marine Biotechnology in August of 1988.
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