Protein analysis and characterization is of critical importance to biopharmaceutical discovery research, development and manufacturing. Understanding the structure and function of therapeutic proteins and their related isoforms is essential for drug candidate screening, assessing manufacturability, process development/optimization, formulation development, quality assurance/quality control, regulatory, and other areas of biomanufacturing. My lab has collaborated with more than fifty biopharmaceutical and biotechnology companies – most of them based in Massachusetts as well as some national and international – over the past twelve years. My research focuses on critical issues that remain unaddressed by industry. These include studying relationships between protein folding and productivity, the mechanism of action (MoA) of protein therapeutics, the adverse effects associated with protein aggregation, and the role of posttranslational modifications in protein structure and function. In addition to working on traditional biopharmaceuticals, I have pioneered structural studies on emerging forms of protein therapeutics, such as bispecific antibodies, complex fusion proteins and antibody drug conjugates (ADCs).
- ECUST, Shanghai, China - Biochemistry B.S.
- University of North Texas, Denton, TX Biochemistry Ph.D.
- University of North Texas, Denton, TX Biochemistry/Biophysics - Postdoctoral Fellowship
- Xu, J., Yang, G., & Gu, Q. (1991) Immobilization of Penicillin Acylase on Chitosan Matrix. Chinese Journal of Antibiotics 15, 338-345.
- Xu, J., & Root, D. (1998) Domain Motion between the Regulatory Light Chain and the Nucleotide Site in Skeletal Myosin. Journal of Structural Biology 123, 150-161.
- Xu, J., and Root, D. (2000) Conformational Selection during Weak Binding at the Actin and Myosin Interface. Biophysical Journal 79, 1498-1510.
- Root, D., Stewart, S., and Xu, J. (2002) Dynamic Docking of Myosin and Actin Observed with Resonance Energy Transfer. Biochemistry 41, 1786-1794.
- Gundapaneni, D., Xu, J., and Root, D. (2005) High Flexibility of the Actomyosin Crossbridge Resides in Skeletal Muscle Myosin Subfragment-2 as Demonstrated by a New Single Molecule Assay. Journal of Structural Biology 149, 117-126.
- Wang Q., Shorten D., Xu J., Shaw G., Schaub R., Shea C., Brooks J., Sako D., Wiswall E., Xu J., Szklut P., and Patel V. (2006) Effect of von Willebrand Factor on the Pharmacokinetics of Recombinant Human Platelet Glycoprotein Ibα-Immunoglobulin G1 Fusion Protein. Pharmaceutical Research 23, 1743-1749.
- Strand J, Huang CT, Xu J. (2013) Characterization of high molecular weight aggregates from a CHO-expressed ECD receptor-Fc fusion protein. Journal of Pharmaceutical Sciences 102, 441-53.
- Bhoskar P, Belongia B, Smith R, Yoon S, Carter TL and Xu J. (2013) Free Light chain content in culture media is related to recombinant monoclonal antibody productivity and quality. Biotechnology Progress 29, 1131-9.
- Su J, Esmaeilzadeh H, Zhang F, Yu Q, Cernigliaro G, Xu J., Sun H. (2018) An ultrasensitive micropillar-based quartz crystal microbalance device for real-time measurement of protein immobilization and protein-protein interaction. Biosen. Bioelectron. 15, 325-331.
- Xu C, Feng AZ, Ramineni CK, Wallace M, Culyba E, Guay K, Mehta K, Mabry R, Farrand S, Xu J. and Feng J. (2019) L445P Mutation on Heavy Chain Stabilizes IgG4 under Acidic Condition. mAbs 11, 1289-1299.