UCR

Center for Plant Cell Biology



Victor Rodgers


Victor RodgersVictor Rodgers

Professor of Bioengineering;
Department Chair

Mailing Address:

Bioengineering
Bourns Hall /A237
University of California
Riverside, CA 92521

Phone: (951) 827-6241
Fax: (951) 827-6416
Email: victor.rodgers@ucr.edu

UCR Living the Promise Profile (2011)
Website

Degree(s):

PhD 1989 Washington University
MS 1985 University of Pittsburgh
BSc 1980 University of Dayton

College/Division Affiliation:

Bourns College of Engineering

Center/Inst Affiliation(s):

Center for Plant Cell Biology
Center for Research in Intelligent Systems (CRIS)

Areas Of Expertise:

Biotransport; Bioreactions in Cells; Thermodynamics of Concentrated proteins in Solution

Awards / Honors:

2006  AAAS Fellow (American Association for the Advancement of Science)
2005  Distinguished Educator Award, The University of Iowa
2004  Catalyst Award, The University of Iowa, for Distinctive and Innovative Diversity Contributions
2004  Collegiate Service Award, The University of Iowa
1999  Distinguished Service Award, AIChE, Minority Affairs Committee
1998  Award for Outstanding Achievement in Teaching, The University of Iowa
1998  Collegiate Teaching Award, The University of Iowa
1997  Hawkeye Engineer Excellence in Teaching, The University of Iowa
1996  Hawkeye Engineer Excellence in Teaching, The University of Iowa
1995  SROP Distinguished Mentor Award,(CIC, Big Ten Universities)
1995   Hawkeye Engineer Excellence in Teaching, The University of Iowa
1992  Salute to Excellence Stellar Achievement Award, (St. Louis American Newspaper)
1992  James N. Murray Faculty Award (Most Outstanding Young Professor), The University of Iowa
1991  Tau Beta Pi Excellence in Engineering Teaching Award>br> 1985  Fellowship, Washington University
1983  Fellowship (G-POP), University of Pittsburgh

Research Summary:

I am the director of the B2K Group (Biotransport and Bioreaction Kinetics Group). Our current research focuses on solving biomedical engineering and systems biology problems associated with a transport phenomena, thermodynamics, and/or kinetic-based emphases. The dominant approach by B2K is mathematical modeling that couples to relative experimental verification. The following summarizes our work relevant to IIGB.

Kinetic Modeling of Reactive Oxygen Species in the Mitochondria<

We are collaborating with Professor Garry Buettner, Department of Radiology in the College of Medicine at The University of Iowa on problems relating to kinetic modeling of reactive oxygen species in the mitochondria. In one project, we are investigating the role of manganese superoxide dismutase (MnSOD) in the rate of formation of hydrogen peroxide. Hydrogen peroxide concentrations are important since it can at as a signaling molecule at low concentrations but acts as a toxin when the concentrations are high. We found that, depending on the reaction rate equilibrium constant, MnSOD can shift the apparent steady-state concentration of H2O2.[1]

In another project we are mathematically investigating the role of glutathione (GSH) in the removal of hydrogen peroxide in cells and tissues. We showed that, despite current beliefs, both [GSH] and [GPx-1] directly impact the time constant for H2O2 removal [2].

Modeling Behavior of Protein Solutions

The behavior of crowded proteins in aqueous solution plays a critical role in biological systems. We are interested in understanding the relationship of protein-solvent and protein-protein interactions to further our understanding of biological systems and to develop improved separation processes. In doing this, we are investigating the behavior of concentrated single and multicomponent protein solutions using osmotic pressure. 

In general, protein solutions behave highly non-ideal. Until now, it was largely accepted that this non-ideality was due to protein-protein interaction. However, recently we have shown that, in many cases, hydration and ion binding could account for the non-idealities for single, highly concentrated, protein solutions at physiological conditions [3-6]. In these cases, the osmotic pressure can be represented as

where, the subscripts 1-3 represent the solvent, proteins and ion species, respectively.  Nj is the initial total moles of solvent in compartment j, vij is the net number of moles of solvent component i that is interacting with protein j, and Nij is the initial total moles of solvent species i in compartment j. Figures 1 and 2 show how the free-solvent model corrects the osmotic pressure.

Figures 1 and 2 show the osmotic pressure in terms of the conventional concentration variable (Figure 3) and when the concentration is expressed in terms of mole fraction using the free-solvent model (Figure 4).

Fig 3

Once more, comparing the seemingly unrelated hydration numbers for each protein to their solvent accessible surface area (SASA) showed that the hydration values represent a monolayer of water. Using the Research Collaboratory for Structural Bioinformatics (RCSB) the protein data base identification (PDB ID) for each protein (or structurally similar protein) was determined. This data provides the unique structure for each globular protein. For lysozyme, ovalbumin, albumin and immuno-gamma globulin the PDB IDs used were 4LYZ, 1OVA, 1AO6, and 1IGT, respectively [7-10]. The SASA for each structure was determined using GETAREA 1.1 with a 1.4 Å probe radius [11]. This model suggested that the solvent-solute contributions, are substantially more significant in describing osmotic pressure than that assumed by virial expansion models based on McMillan-Mayer theory [12]. We have also shown that this free solvent model is effective for crowded binary protein solutions as well with predictions that include no fitting parameters [13].

REFERENCES

[1] Buettner G.R., Ng C. F., Rodgers V.G.J., Schafer F.Q., “A New Paradigm: Manganese Superoxide Dismutase Influences the Production of H2O2 in Cells and Thereby their Biological State”, Free Radical Biology and Medicine, 41(8) 1338-1350 (2006).

[2] Ng, C.F., Schafer, F.!., Buettner, G.R., Rodgers, V.G.J., "Cellular hydrogen peroxide removal shows dependency on effective GPx activity: Mathematical insight into observed in-vivo behavior", in press, Free Radical Research, (2007).

[3] Yousef, M. A., Datta, R., and Rodgers, V. G. J., “Free-Solvent Model of Osmotic Pressure Revisited. Application to Concentrated IgG Solution at Physiological Conditions”, Journal of Colloid and Interface Science, 197 108-118 (1998).

[4] Yousef, M. A., Datta, R., and Rodgers, V. G. J., “Understanding Non-Idealities of the Osmotic Pressure of Concentrated Bovine Serum Albumin”, Journal of Colloid and Interface Science, 207:2 273-282 (1998).

[5] Yousef, M. A., Datta, R., and Rodgers, V.G.J., “Confirmation of Free-Solvent Model Assumptions in Predicting the Osmotic Pressure of Concentrated Globular Proteins”, Journal of Colloid and Interface Science 243 321-325 (2001).

[6] Yousef, M. A., Datta, R., and Rodgers, V.G.J., “Monolayer Hydration Governs Nonideality in Osmotic Pressure of Protein Solutions”, AIChE Journal, 48(6) 1301-1308 (2002).

[7] Diamond, R., “Real-Space Refinement of the Structure of Hen Egg-White Lysozyme”, J. Mol. Biol., 82, 371 (1974).

[8] Stein, P. E., Leslie, A. G., Finch, J. T., Carrell, R. W., J. Mol. Biol. 221, 941 (1991).

[9] Carter, D. C., Ho, J. X., Adv. Protein Chem. 45, 153 (1994).

[10] Harris, L. J., Larson, S. B., Hasel, K. W., McPherson, A., Biochemistry 36, 1581 (1997).

[11] Fraczkiewicz, R. and Braun, W., "Exact and Efficient Analytical Calculation of the Accessible Surface Areas and Their Gradients for Macromolecules." J. Comp. Chem. 19, 319 (1998).

[12] McMillan, W.G., and Mayer, J.E., J. Chem. Phys. 13:7 276-305 (1945).

[13] Yousef, M. A., Datta, R., and Rodgers, V.G.J., “Model of Osmotic Pressure for High Concentrated Binary Protein Solutions”, AIChE Journal, 48(4), 913-917 (2002).


Related Press Releases:


Selected Publications:

List of publications from HubMed

Lab Personnel:

McBride, Devin
Graduate Student Researcher —
Vandrangi, Prashanthi
Graduate Student Researcher —
Buccola, Jana
Graduate Student Researcher  —
Dhall, Sandeep
Graduate Student Researcher —
 

More Information

General Campus Information

University of California, Riverside
900 University Ave.
Riverside, CA 92521
Tel: (951) 827-1012

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Center Information

Center for Plant Cell Biology
Botany & Plant Sciences Department
2150 Batchelor Hall

Tel: (951) 827-7177
Fax: (951) 827-5155
E-mail: genomics@ucr.edu

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