Deducing the Macromolecular Organization of Arabidopsis Thaliana Leaf Cuticles by Solid-State NMR

Abstract

are able to form extraordinarily stable vesicular membranes against a number of chemical, physical and mechanical stressors. In this study, we demonstrated that PLFE can also form free-standing ''planar'' membranes on micro-pores (~100 micrometer) of polydimethylsiloxane (PDMS) thin films embedded in printed circuit board (PCB)-based fluidics. Using electrochemical impedance spectroscopy (EIS), we found that the dielectric properties of PLFE planar membranes suspended on the PDMS films are distinctly different from those obtained from diester lipid and triblock copolymer membranes. In addition to resistance (R) and capacitance (C) that were seen in all the membranes examined, PLFE planar membranes showed an inductance (L) component. Furthermore, PLFE planar membranes displayed a relatively large membrane resistance, suggesting that, among the membranes examined, PLFE planar membrane would be a better matrix for studying channel proteins and transmembrane events. PLFE planar membranes also exhibited a sharp decrease in phase angle with the frequency of the input AC signal at~1 MHz, which could be utilized to develop sensors for monitoring PLFE membrane integrity in fluidics. Since the stability of free-standing planar lipid membranes increases with increasing membrane packing tightness and PLFE lipid membranes are more tightly packed than those made of diester lipids, PLFE free-standing planar membranes are expected to be considerably stable. All these salient features make PLFE planar membranes particularly attractive for model studies of channel proteins and transmembrane events and for high-throughput drug screening. Terrestrial plants regulate environmental interactions via insoluble polymers assembled in their epidermal and/or peridermal cell walls. The plant cuticles with waterproofing and antimicrobial capabilities represent a unique class of biological assemblies composed of ester-linked and insoluble constituents such as biopolyester cutins, lipid waxes, and chemically recalcitrant cutans. Solid-state nuclear magnetic resonance (NMR) offers a powerful technique to probe the structural and dynamical properties of these geochemically important and structurally amorphous biological systems that can also motivate the engineering of water-resistant bioinspired materials from renewable sources. Based on key genes and biosynthetic pathways identified in Arabidopsis thaliana leaf cuticles, our current solid-state NMR study delineates compositional variations and multiple-timescale (ms-ns) dynamics for several genetically tailored and insoluble plant cuticle systems, linking macromolecular organization with protective performance and operational design. 2454-Pos Board B591Injectable Reverse Thermal Gel Biopolymers may Act as an Extracellular Matrix and Cell Vehicle for Cardiac Tissue Engineering Background: Recent investigations demonstrated that tissue engineering represents a promising strategy to repair diseased hearts. We hypothesized that temperature-responsive materials could be developed as extracellular ma...