Poster Session I

Author Information

Project Type

Poster

Project Funding and Affiliations

CTM Summer Undergraduate Research Internship

Faculty Mentor’s Full Name

Orion Berryman

Faculty Mentor’s Department

Chemistry

Additional Mentor

tony.shelton@umconnect.umt.edu

Abstract / Artist's Statement

Cells use ion transport pathways for osmosis, electrochemical gradients, signaling, and programed cell death. When natural ion channels fail, synthetic alternatives are needed. This project explores the ability of synthetic “transporter” molecules to bind anions (negatively charged atoms) and carry them across lipid bilayers. Preliminary results have shown Hydrogen Bond enhanced Halogen Bonding (HBeXBing) molecules can facilitate anion transport more efficiently than known XBing anion transporter pentafluoroiodobenzene (PFIB). The hydrophobic functional groups clearly increase transport rates of these molecules. We expect that EC50 and Hill coefficients will indicate highly active transporters. Currently the liposome procedure is being optimized to achieve stable vesicles (less than 10% leakage over 200 seconds), which is required for accurate rate analysis. The most recent protocol shows 13% leakage of the liposomes.

To model cellular membranes, large unilamellar vesicles (liposomes) are formed using POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) which is the main lipid component in mammalian cells. The liposomes are loaded with a pH-sensitive fluorescent dye (HPTS). G2XB, G3XB, and 9mer are halogen bonding molecules that were synthesized at UM. The ability of these transporters is directly measured via pH-based fluorescent changes. Since these molecules are not capable of also carrying a proton (H+), extremely efficient proton shuttling channel gramicidin is added to address this rate-limiting step. The HBeXBing motif in these molecules can be used to study or design new synthetic therapeutics that target Cystic Fibrosis and other channelopathies.

Category

Physical Sciences

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Apr 17th, 10:45 AM Apr 17th, 11:45 AM

Hydrogen Bond enhanced Halogen Bonding Anion Transporters

UC South Ballroom

Cells use ion transport pathways for osmosis, electrochemical gradients, signaling, and programed cell death. When natural ion channels fail, synthetic alternatives are needed. This project explores the ability of synthetic “transporter” molecules to bind anions (negatively charged atoms) and carry them across lipid bilayers. Preliminary results have shown Hydrogen Bond enhanced Halogen Bonding (HBeXBing) molecules can facilitate anion transport more efficiently than known XBing anion transporter pentafluoroiodobenzene (PFIB). The hydrophobic functional groups clearly increase transport rates of these molecules. We expect that EC50 and Hill coefficients will indicate highly active transporters. Currently the liposome procedure is being optimized to achieve stable vesicles (less than 10% leakage over 200 seconds), which is required for accurate rate analysis. The most recent protocol shows 13% leakage of the liposomes.

To model cellular membranes, large unilamellar vesicles (liposomes) are formed using POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) which is the main lipid component in mammalian cells. The liposomes are loaded with a pH-sensitive fluorescent dye (HPTS). G2XB, G3XB, and 9mer are halogen bonding molecules that were synthesized at UM. The ability of these transporters is directly measured via pH-based fluorescent changes. Since these molecules are not capable of also carrying a proton (H+), extremely efficient proton shuttling channel gramicidin is added to address this rate-limiting step. The HBeXBing motif in these molecules can be used to study or design new synthetic therapeutics that target Cystic Fibrosis and other channelopathies.