Tanxing Cui

Contact Information:

Email: tac21@pitt.edu

Education:
2004 MS biophysics Nankai University in China
2001 BS Physics Nankai University in China

Research:
Until now, only one percent of proteins with known structures belong to membrane proteins. In structural biology, determining membrane protein structures is still challenged, due to low expression level, unpredictable folding process, and less stability. Particularly, because of their highly hydrophobic nature, membrane proteins are most likely to form aggregation over time. The nonspecific aggregation can prevent membrane proteins from being structurally analyzed by NMR spectroscopy or X-ray crystallography. We cooperate with university of Pennsylvania and develop a novel method. Through mutating on the specific lipid-contacting sidechains to more polar groups and without touching the amino acids that involve the interaction between helices, the membrane proteins can be pulled off from the membrane into the water or micelles formed by detergents. In such way, membrane proteins can exist in the monodispersion state, highly concentrated and ‘visualized’ by NMR spectroscopy. In other words, membrane proteins can be solubilized or ‘partially’ solubizlized. My work mainly focuses on determining the structure of nicotine acetylcholine receptor through using this novel method. A diverse range of molecules, from structurally featureless noble gases to complex steroids, can cause people into a state known as general anesthesia. The molecular processes underlying this phenomenon remain unclear. Cooperate with university of Pennsylvania, a novel dimeric protein, (Aα2-L1M/L38M)2, was engineered by de novo design to create a long hydrophobic core within a common four-α-helix bundle scaffold, which has a clinic anesthetic binding affinity. Through using NMR, we investigate general anesthetic effect on the structure and dynamic of (Aα2-L1M/L38M)2. Wild type membrane protein is hard to be studied by NMR spectroscopy. Usually, the recombinant chimeric membrane protein is generated for NMR study. However, whether the recombinant protein is still functional is critical. We reconstitute chimeric recombinant protein into lipid vesicles and use fluorescent probe to characterize the function of recombinant protein.

PhD Advisor:
Dr. Yan Xu
Dr. Pei Tang

Research Advisor:
Dr. Yan Xu, NMR Assignment of a Four-Helix Bundle Protein
Dr. John Rosenberg, Calibration and Experimentation in Crystallogcraphy lab Robots
Dr. Eric T. Ahrens, MRI and biology

Publications:
1. Cui T, Bondarenko V, Ma D, Canlas C, Brandon NR, Johansson JS, Xu Y, Tang P. (2008) Four-alpha-helix bundle with designed anesthetic binding pockets. Part II: halothane effects on structure and dynamics. Biophys J. 94, 4464-72
2. Ma, D. Brandon, N. R. Cui, T. Bondarenko, V. Canlas, C. Johansson, J. S. Tang, P. Xu, Y. (2008) Four-alpha-helix bundle with designed anesthetic binding pockets. Part I: structural and dynamical analyses. Biophys J. 94, 4454-63
3. Cui T, Cai K, Chen S, Chen M, Qiao Y. The computer simulation of Bio-electrical Impedance Tomography. Acta Scientiarum Naturalium Universitatis Nankaiensis.
4. Cai K, Cui T, Qiao Y. A multifunction sensor for blood flow and oxygen saturation detection. Chinese Journal of Scientific Instrument
5. Qiao Y, Cai K, Qiao F, Cui T, Chen S. The design of a new-type system of laser Doppler microvascular analyzer. Acta Scientiarum Naturalium Universitatis Nankaiensis.
6. Qiao Y, Cai K, Qiao F, Chen S, Cui T. The design of a multifunction blood flow and oxygen saturation detection system. Acta Scientiarum Naturalium Universitatis Nankaiensis.
Selected presentation

NMR Study of a Four-α-Helix Bundle with Bound anesthetics. Poster presented on the 51st Annual Biophysical Society Meeting, Baltimore, MD.
Fellowships and Awards

Oct. 2003, Third-Class Scholarship of Nankai University
Oct. 2000, Fundamental Scholarship of Nankai University