Qiuwei Xu's Curriculum Vitae

Qiuwei Xu

Home: 410-653-2092
Work: 410-455-3025
E-mail: qiuxu@model.chem.umbc.edu
Home page: http://www.research.umbc.edu/~qxu

Research Associate, University of Maryland (1/93-Present).

1. Apply molecular modeling, dynamics simulation and NMR to study conformation and dynamics of antigen and lectin binding sites of bacterial polysaccharides.
   • Measure Long-Range ¹³C-¹³C J coupling on uniformly ¹³C enriched polysaccharide through Bax's quantitative method;
   • Measure ³J_HH on uniformly ¹³C enriched polysaccharide through HCCH- E.COSY method;
   • Measure C-13 relaxation rates on uniformly ¹³C enriched polysaccharide with selective C-13 pulses. Interpret relaxation rates in terms of reduced spectral density function and model-free formalism with self-programmed software;
   • Measure proton NOE and ³J_CH from three-dimensional HMQC-NOESY;
   • Locate conformation ensembles of flexible polysaccharide according to ³J_CH with the singular value decomposition method (SVD), and confirm NOE match with complete relaxation matrix analysis;
   • Run dynamics simulation with three bound coupling constant constraints I build in user subroutine of modeling software CHARMm;

2. Complete chemical structure determination of polysaccharide from V. cholera, V. vulnificus with NMR, HPLC, GC and CD.
   • Elucidate chemical structure of polysaccharide with COSY, TOCSY, HMQC, HMBC (H1-C13 and H1-P31 correlation).

3. Maintain and trouble-shoot instrument hardware, set up automatic instrumental control:
   • Upgrade and maintain GE-Omega 500 NMR instrument.

4. Write various programs in C, FORTRAN and C++ and shell scripts to assist modeling and data analysis:
   • streamline data process by connecting different software output and input with shell scripts and self-coded programs;
   • program in C and FORTRAN for non-linear data fitting;
   • program in C of singular value decomposition scheme to do conformation search in modeling;
   • program user subroutine in CHARMm for ³J-constrained dynamics simulation;
   • program in C, C++ and Java to build data base, sort data and do semi-automatic spectrum assignment;
   • using Java and HTML to present research results and real time modeling and molecular dynamics on world wide web and online scientific conference;
   • set up methods for remote instrumental control and operation;
   • program in FORTRAN to simulate proton spin relaxation matrix.

Research Assistant, Polytechnic University & University of Nebraska-Lincoln (2/90-12/92).

1. Study specific recognition of polyvalent cation on DNA with ligand-docking.
2. Probe DNA conformation perturbation by cation with NMR and CD.
3. Measure binding thermodynamics parameters with NMR and equilibrium dialysis.
4. Apply multi-quantum filtered metal cation NMR in probing K+, Na+ binding environments in DNA telomere G-quartet.
5. Program in C, FORTRAN and BASIC to do non-linear data fitting for ligand- DNA binding.
6. Workstation system management.

Research Assistant, Polytechnic University (7/89-1/90)

1. Synthesize optical active polymer.
2. Study its conformation and phase transition with DSC, CD and ORD.

Research Assistant, Polytechnic University(7/87-6/89)

1. Synthesize polyvinyl chloride and its degradation inhibitors.
2. Use GC-MS, NMR, UV and FTIR to study polyvinyl chloride degradation mechanism.

Internship, China Textile University(9/84-7/87)

1. Design and scale-up production of high density polyethylene gel spinning.
2. Characterization of polymer using DSC, DMA, TGA, x-ray diffraction, and Tensile tester.

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Degrees

1992

Ph.D. in Chemistry from University of Nebraska-Lincoln; Lincoln, Nebraska

1988

M.S. in Polymer Chemistry from Brooklyn Polytechnic University; Brooklyn, New York

1985

B.Chem.Eng. in Polymer Engineering from China Textile University; Shanghai, China

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Publications

1. Q. W. Xu & C. A. Bush "Dynamics of ¹³C enriched cell wall polysaccharide S. mitis J22 studied by ¹³C T₁, T_1r and ¹³C-{¹H} NOE" Biochemistry 35, 14512-14520 (1996)

2. Q. W. Xu & C. A. Bush "Molecular modeling and dynamics of the flexible cell wall polysaccharide S. mitis J22 solely based on ³JCH and checked with proton NOE" Biochemistry 35, 14521-14529 (1996)

3. Q. W. Xu, S. Mohan & C. A. Bush "A flexible model for the cell wall poly- saccharide of S. sanguis J22 determined by three dimensional ¹³C filtered NOESY spectra and ¹³C-¹H long range coupling constants combined with molecular modeling" Biopolymers 38, 339-353 (1996)

4. Q. W. Xu, R. Gitti, and C. A. Bush "Comparision of NMR and Modeling Results for a Rigid and a Flexible Oligosaccharide" Glycobiology 6, 281-288 (1996)

5. Q.W. Xu, S. Jampani, H. Deng, and W. H. Braunlin "Chiral recognition of deoxyoligonucleotides by D and L tris(ethylenediamine)cobalt(III)" Biochemistry 34, 14059 (1995)

6. L. Preston, Q.-W. Xu, J. A. Johnson, A. Joseph, D. R. Maneval, Jr., K. Husain, G. P. Reddy, C. A. Bush, J. G. Morris, Jr. "Preliminary Structure Determination of the Capsular Polysaccharide of Vibrio Cholera O139 Bengal Al1837" J. Bact. 177, 835 (1995)

7. Q. W. Xu, H. Deng, and W. H. Braunlin "Selective Localization and Rotational Immobilization of Monovalent Cations on Quadruplex DNA" Biochemistry 32, 13130 (1993)

8. Q. W. Xu, Srinivas Rao B. Jampani, and W. H. Braunlin "The Rotational Dynamics of Hexaammine Cobalt(III) Bound to Oligomeric DNA: Correlation with Cation-induced Structural Transitions" Biochemistry 32, 11754 (1993)

9. Q. W. Xu, R. K. Shoemaker & W. H. Braunlin "Induction of B-A Transitions of Deoxyoligonucleotides by Multivalent Cations in Dilute Aqueous Solution" Biophys. J. 65,1039 (1993)

10. W. H. Braunlin & Q.-W. Xu "Hexaamminecobalt(III) Binding Environments on Double-Helical DNA" Biopolymers 32, 1703 (1992)

11. Q. Xu, C. A. Bush "Modeling a polysaccharide with ³J_CC and ³J_CH" in preparation (1996).

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References

Available upon request.

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