Wensi Vennekate, PhD, Postdoctoral Fellow
During my PhD study I worked in the Group of Biomolecular Spectroscopy and Single-Molecule Detection (Prof. PJ Walla) and Dept. of Neurobiology (Prof. R Jahn) at the Max-Planck-Institute for Biophysical Chemistry, Germany. My research was focused on the neuronal membrane fusion using fluorescence correlation-spectroscopy (FCS).
I joined the Karatekin lab in April 2013. My goal is to reconstitute SNARE-mediated membrane fusion of single proteoliposomes with supported lipid bilayers in microfluidic channels using TIRF microscopy. The microfluidic channels are made by sticking a PDMS block on a piece of ultra clean coverslip (Karatekin and Rothman, Nature Protocols, 2012). After pulling the liposomes into the channel using a syringe pump, the liposomes burst on the coverslip and form a uniform, planar, fluid bilayer of membrane bearing t-SNAREs. The bilayer is cushioned with a soft, hydrated polymer layer to avoid interactions between the t-SNAREs and the glass surface. The method was established a few years ago for SNARE-only fusion. We are now testing the roles of various proteins that regulate the fusion reaction, as well as physical parameters such as vesicle curvature. A parallel goal is to make the assay more robust and allow use of more physiological lipid compositions containing cholesterol.
I am also involved in a new assay developed in the lab to study single pores formed between nanodiscs carrying v-SNAREs and cells expressing “flipped” t-SNAREs on their surfaces (Z. Wu, S. M. Auclair, O. Bello, W. Vennekate, S. Krishnakumar, and E. Karatekin, submitted).