ABEL at the University of Cincinnati 

The Advanced Biomolecular Engineering Lab (ABEL) at the University of Cincinnati College of Engineering seeks to overcome modern environmental and human health challenges by creating synthetic biological solutions. For the environment, this can range from bacterial multidrug efflux pumps for water purification to artificial photosynthesis in frog surfactant-based foam. Medically relevant research includes light activated pancreatic beta-cells, gap junction electrophysiology and biological nanopore for DNA sequencing and sensing. The common theme for ABEL is applying the exquisite design and functionality evolution has built into the proteins and nucleic acids of the natural world as tools for nanoscale design and engineering.

Applying Multidrug Efflux Pumps for Water Purification

solar-powered nanofilter

Using the mechanism bacteria use to shrug off powerful antibiotics, scientists have developed solar-powered nanofilters that remove antibiotics from lakes and rivers twice as efficiently as the best existing technology.
Credit: American Chemical Society (Michael Woods)

"Engineering Bacterial Efflux Pumps for Solar-Powered Bioremediation of Surface Waters"

Using the same devious mechanism that enables drug resistant bacteria to shrug off powerful antibiotics, the Wendell Lab has developed solar-powered nanofilters that remove antibiotics, carcinogens and hormones from the water in lakes and rivers twice as efficiently as the best existing technology.

Antibiotics from toilets, farming and healthcare facilities find their way into lakes and rivers, with traces appearing in 80 percent of waterways. Those antibiotics foster emergence of new antibiotic-resistant bacteria, while harming beneficial microbes in ways that can degrade aquatic environments and food chains. Filters containing activated carbon can remove antibiotics at municipal water treatment facilities, but activated carbon is far from perfect.

Using the very proteins that enable bacteria to survive doses of antibiotics, carcinogens and heavy metals, we have engineered a solar powered water filtration system to clean surface water. Multidrug efflux pumps represent an exciting nanoscale filtration tool, capturing a host of noxious compounds, but still selective enough to ignore many harmless organics. Normally these protein efflux pumps expel antibiotics from bacterial cells, but we have turned it around, so that the system captures compounds within our vesicles. That way, they can be collected and recycled or shipped for disposal. Future work will pursue adapting the technology to remove hormones, heavy metals and other undesirable materials from water.

Connexin Hemichannel Electrophysiology

Connexin 43 is the most ubiquitous gap junction protein in the human body and is essential for cell-to-cell communication in a variety of organs and organ systems. As a result, Cx43 is responsible for mediating both electrical and chemical signals, passing dissolved solutes and small signaling molecules between cells in a coordinated fashion. Recent work explores the electrophysiological properties of hemichannels formed from Cx43 and Cx43 fused to eGFP (Cx43eGFP) and their interactions in a planar lipid membrane (BLM). Unlike in vivo patch clamp experiments, Cx43 was purified and isolated from other membrane constituents allowing elucidation of individual protein responses to various electrical and chemical stimuli. Using this system, we examined hemichannel electrophysiology and the roles of several well-known gap junction blockers, namely: lanthanum, heptanol, carbenoxalone and lindane. We also observed a critical number of hemichannels required for an accelerated conductance increase, an emergent electrical signature indicative of plaque formation.

The manuscript can be found here: "Electrophysiology of Single and Aggregate Cx43 Hemichannels"

Artificial Photosynthesis

Image Credit: Megan Gundrum with text from Wendy Beckman

In natural photosynthesis, plants use solar energy and carbon dioxide to make oxygen and sugars. Unfortunately, the allocation of light energy into products we use is not as efficient as we would like.

Cover art for Nano Letters.

The work focused on making a new artificial photosynthetic material which uses plant, bacterial, frog and fungal enzymes, trapped within a foam housing, to produce sugars from sunlight and carbon dioxide.

Foam was chosen because it can effectively concentrate the reactants but allow very good light and air penetration. The design was based on the foam nests of a semi-tropical Tungara frog, which creates very long-lived foams for its developing tadpoles. The work can be found here: “Artificial Photosynthesis in Ranaspumin-2 Based Foam

The advantage of this system compared to plants is that all of the captured solar energy is converted to sugars, whereas plants must divert a great deal of energy to other housekeeping functions to maintain life and reproduce. The foam uses no soil, so food production would not be interrupted, and it can function in highly enriched carbon dioxide environments, like the exhaust from coal-burning power plants, unlike many natural photosynthetic systems.

Future work will examine pairing foam production with algae grown for fuel, algal cytoplasmic contents separated from the oils used for biodiesel can be reused in the foam, augmenting carbon capture and fuel production.

Biological Nanopores

The phi29 bacteriophage is Bacillus specific virus with one of the strongest dsDNA packaging machines discovered. Dr. Wendell's intial work applying GP10 as a dsDNA sensor was published in Nature Nanotechnology: "Translocation of double-stranded DNA through membrane-adapted phi29 motor protein nanopores"

ABEL has recently investigated the electrophysiology of a pore mediated by the native GP10 capsid protein to determine DNA sensing locations ideal for protein engineering. Several biological nanopores have been engineered for stochastic sensing and DNA sequencing applications the aperture size and observed electrical stability of GP10 makes it an equally attractive candidate, in the Wendell Lab this has focused on applying GP10 for cancer detection. While divergent in sequence, a number of dsDNA packaging motors have common structural features including portal proteins, which could allow a variety of nanopores to be put to work as nanopore DNA sequencers and sensors.

Upcoming Work

Metagenomic Investigations for Greywater Risk Assessment

Solar-based Selective Disinfection

Cancer Sensing Biological Nanopores

Also stay tuned for: Light Activated Pancreatic Beta-Cells,Organic Antifungal Treatment, ATP Photoswitch, and others...

Last Updated: 5/1/2013