2014.10.20 Bio-inspired DNA nano-devices for membrane engineering
Title：Bio-inspired DNA nano-devices for membrane engineering
Speaker： Dr. Chenxiang Lin
Assistant Professor of Cell Biology, Yale School of Medicine
Time： 1:00pm Oct 20th 2014
Address： Rm 102, East wing of Old Chemistry Building, Peking Unversity
Chair： Prof. Luhua Lai, Center for Quantitative Biology
Lipid membranes serve as barriers to define the boundaries of a cell and its subcellular compartments. With the help of membrane-associating molecules, they can undergo dramatic structural changes during vesicular transport processes and mediate complex reactions that are vital to cell division, growth and death. Inspired by such elegance in nature, bioengineers and synthetic biologists have aspired to build artificial membranes to mimic the vesicular transport machineries. In addition, such in vitro preparations provide a “clean” system for cell biologists and biophysicists to study functional interactions between membranes and their associating molecules. Despite the advanced chemical and physical methods that are now available to manipulate and observe lipid membranes, two technical challenges have hampered our ability to construct a completely artificial system that mimics natural membrane systems. First, it has been difficult to produce large quantities of mono-dispersed lipid vesicles with well-defined structure (size & shape). Second, it has been challenging to regulate the membrane dynamics (fusion, fission, etc.) in a programmable way.
Here we present our lab’s recent effort (in collaboration with William Shih lab and James Rothman lab) to resolve these technical limitations. Our approach is to use self-assembled DNA nanostructures as templates to guide the assembly of lipid bilayers and the membrane associating proteins, and transduce the programmable feature of the DNA nanostructures to the templated vesicles. First, we show our ability to manufacture DNA-templated spherical liposomes with defined size ranging from 30-80 nm. Second, we show our preliminary studiesto regulate membrane fusion kinetics by controlling the number of SNARE complexes at the fusion site through the DNA-guided proteoliposome assembly approach.