School of Medicine

Wayne State University School of Medicine

Profile View

JianJun Wang
Title
Professor
Phone
313-577-8836
Profile

Research in our laboratory focuses on two major human diseases: heart disease and Alzheimer's disease. We are using structural biology, molecular biology, protein chemistry, biophysics and protein engineering techniques in our research. Our research objectives are centered on solving the structures of several critical proteins that are involved in cholesterol transport in the peripheral tissues and in the brain. In addition, my laboratory is developing in cell structural biology technique for real time observation and visualization of protein folding, structural changes, post-translational modification, protein-protein interaction and protein trafficking in living mammalian cells.

Apolipoprotein E (apoE) and LDL receptor are the two critical proteins that are involved in the LDL receptor mediated endocytosis of LDL particles. One project in our lab is to determine the NMR structure of human apoE and to study apoE/apoE receptor interactions. Using protein engineering technique, we prepared a monomeric, biologically active apoE for NMR study. To determine the NMR structure of apoE, we developed a high efficient on column ligation technique, allowing us to prepare segmental labeled apoE for simplifying the NMR spectra. We have completely assigned NMR To study apoE/apoE receptor interactions, we developed a high efficient in vivo refolding technology, allowing us to prepare large quantity of properly folded and functional ligand-binding domain (LBD) of apoE receptor 2 and VLDL receptor. We are currently working on structural studies of apoE and LBD of VLDL receptor complexes.

In the reverse cholesterol transport pathway, HDL plays a key role. During HDL assembly and transport, several critical proteins play important roles, including apolipoprotein A-I (apoAI), ABC-AI, LCAT and the HDL receptor (SR-BI). ApoAI is especially critical for HDL formation, maturation and transport. Another project is to determine the HDL structures, including lipid-free apoAI, prebeta-HDL, discoidal HDL and spherical HDLs. We have determined NMR structure of lipid-free apoAI and completely assign the NMR spectra of prebeta-HDL. For high-resolution structural studies of HDL particles, including discoidal and spherical HDLs, we developed a very high yield bacterial expression method, allowing us to produce 500-1000 mg purified protein from one-liter cell culture. We further developed a method that allows us to obtain ultra-pure HDL particles for structural determination. We are currently working on NMR structural studies of these HDL particles. We further prepared large quantity of properly refolded and post-translationally modified LCAT and SR-BI. Future studies will include ABC-AI, LCAT and SR-BI. Since a low level of plasma HDL and a compromised HDL function are the common thread of metabolic disorders/diseases including: atherosclerosis, diabetes, obesity, stroke, and Alzheimer's disease, the results obtained from these studies should have significant implications for the design of new medicines to treat these metabolic disorders/diseases.

We recently developed a novel QQ protein transduction technology, allowing us to efficiently deliver protein into living mammalian cells. We further confirmed that the QQ-reagent delivered proteins are properly refolded and post-translationally modified and follow the same secretion/trafficking pathway as their endogenous counterparts. Using this QQ protein transduction technology, we are working on developing 3D/4D fluorescence imaging technique for real-time investigation/visualization of protein folding, structural changes, post-translational modification, protein-protein interaction and protein trafficking in living mammalian cells.

Graduate
Ph.D. Nanjing University, Nanjing, P. R. China, 1988
Interests

Research Areas:
1. Structure and functions of apolipoproteins and lipoproteins.
2. Heart disease.
3. Alzheimer's disease.
4. Development of ultra-high resolution in cell structural biology techniques.

Techniques used in our research: Molecular biology, protein chemistry, chemical biology, protein-engineering, mammalian cell culture, NMR, CD, ITC and Live cell fluorescence imaging
 

Publications

Sivashanmugam A and Wang J. (2009). NMR structure and dynamics of the N-terminal domain of human apolipoprotein E. J. Biol Chem (in press)

Chen B, Ren X, Neville T, Jerome W G, Hoyt D. W., Ren G, Sparks D and Wang J. (2009). Tertiary Structures of Apolipoprotein AI Determine Stability and Functions of Discoidal High-Density Lipoproteins. Protein Science (in press).

Sivashanmugam A, Murray V, Cui C, Yang Y, Wang J & Qianqian Li (2009). Practical protocols for production of very high-yield of recombinant proteins in Eschericia coli. Protein Science. (in press).

Zhang Y, Chen J and Wang J. (2008). A complete backbone spectral assignment of human apolipoprotein E. Biomol. NMR. Assign 2: 207-210.

Carnemolla, R. Ren X, Biswas T. Meredith SC., Reardon CA, Wang J and Getz GS (2008). The specific amino acid sequence between helices 7 and 8 influences the binding specificity of human apolipoprotein A-I for HDL subclasses: a potential for HDL preferential generation. J. Biol. Chem. 283(23):15779-88.

Zhao W., YH Zhang, Cui C.X., Q. Li and Wang J. (2008). An efficient On-column Expressed Protein Ligation Strategy, Application to Segmental Triple Labeling of Human Apolipoprotein E3. Protein Science 17, 736-747.

Li Q, Huang Y, Xiao N., Murray V, Chen J and J Wang (2008). Real Time Investigation of Protein Folding, Structure, and Dynamics in Living Cells. A invited review in Method in Cell Biology 90, 287-325.

Sivashanmugam A. Yang Y., Murray VL., McCullough C., Q Li and J Wang (2008). Structural Basis of human high-density lipoprotein assembly at atomic resolution. An invited review for Method in Cell Biology (MCB) 90: 327-364.

Yang Y. and Wang J (2007). A complete NMR spectral assignment of lipid-free mouse apolipoprotein A-I C-terminal truncation mutant, apoAI(1-216). Biomol. NMR. Assign 1:109�111

Ren X, Yang Y, Neville, T., Sparks D and Wang J (2007). A complete backbone spectral assignment of human apoAI/pre HDL particle. Biomol NMR Assign 1:69�71.

Zhang Y., Vasudevan S., Sojitrawala R., Zhao W. Cui C., Xu C., Fan D., Newhouse Y., Balestra R., Jerome W. G, Weisgraber K, Li Q. and Wang J. (2007). A monomeric, biologically active, full-length human apolipoprotein E Biochemistry 46, 10722-10732.

Chen J., Li Q Bu. G and Wang J (2007). A complete spectral assignment of a truncation mutant of MESD, a specialized champeron protein for the LDL receptor superfamily. Biol NMR Assignment 1:3�5.