Poster Session II

Project Type

Poster

Project Funding and Affiliations

Integrated Structural Biology Core, Center for Biomolecular Structure & Dynamics, Division of Biological Sciences, NIGMS P20GM103474 Montana INBRE & NIGMS P30GM140963

Faculty Mentor’s Full Name

Levi J. McClelland

Faculty Mentor’s Department

Division of Biological Sciences

Additional Mentor

Cindee Yates-Hansen, Cindee.Yates-Hansen@mso.umt.edu, Brad Benjamin, brad.benjamin@mso.umt.edu

Abstract / Artist's Statement

G protein coupled receptors (GPCRs), a major and diverse group of membrane receptors, are responsible for transducing extracellular signals (ligands) to activate intracellular metabolic pathways. In fact, over a third of FDA approved drugs target GPCRs. Research on GPCR activity contributes significantly to pharmacology and medicine. Signal transduction results in a conformational change activating guanine nucleotide binding proteins (G proteins) by exchanging GDP for GTP. G proteins form heterotrimers consisting of alpha (𝜶), beta (β), and gamma (γ) subunits. From a Gαi specific nanobody (~15 kDa), we have derived 3 megabody constructs ranging in molecular weight from ~55-100 kDa. Megabodies are protein scaffolds containing a grafted nanobody, increasing their molecular weight while maintaining affinity and antigen binding specificity. Here we investigate the potential of these megabodies i) to serve as structural scaffolds in protein crystallography and cryogenic electron microscopy studies, and ii) to function as large molecular weight Gαi folding chaperones. Towards those aims, we complex megabody CA15960 with ΔN31G⍺i to conduct crystallization screens for macromolecular x-ray structure determination and prepare samples for cryogenic electron microscopy experiments.

Category

Life Sciences

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Apr 17th, 2:30 PM Apr 17th, 3:30 PM

Gαi megabodies as a structural scaffold: Complexing megabody CA15960 and ΔN31G⍺i

UC South Ballroom

G protein coupled receptors (GPCRs), a major and diverse group of membrane receptors, are responsible for transducing extracellular signals (ligands) to activate intracellular metabolic pathways. In fact, over a third of FDA approved drugs target GPCRs. Research on GPCR activity contributes significantly to pharmacology and medicine. Signal transduction results in a conformational change activating guanine nucleotide binding proteins (G proteins) by exchanging GDP for GTP. G proteins form heterotrimers consisting of alpha (𝜶), beta (β), and gamma (γ) subunits. From a Gαi specific nanobody (~15 kDa), we have derived 3 megabody constructs ranging in molecular weight from ~55-100 kDa. Megabodies are protein scaffolds containing a grafted nanobody, increasing their molecular weight while maintaining affinity and antigen binding specificity. Here we investigate the potential of these megabodies i) to serve as structural scaffolds in protein crystallography and cryogenic electron microscopy studies, and ii) to function as large molecular weight Gαi folding chaperones. Towards those aims, we complex megabody CA15960 with ΔN31G⍺i to conduct crystallization screens for macromolecular x-ray structure determination and prepare samples for cryogenic electron microscopy experiments.