Virginia Walker - Professor

Research: Our research interests all concern stress genes and the molecular basis of resistance. This is a central question for scientific goals as diverse as predicting the outcome of cancer chemotherapy or planning the impact of global temperature fluctuations. For example, a study on the effects of methotrexate in fruit flies holds promise for understanding developmental abnormalities seen in human babies when mums are prescribed this drug. Similarly, nanoparticle administration may also impact development, and experiments on this potential stress are ongoing.



Environmental stress also challenges organisms, and we know that resistance to winter conditions has resulted in the evolution of stress genes encoding desiccation, cold and ice-binding proteins, including antifreeze proteins. We have cloned a number of these genes from sources as diverse as insects, plants and bacteria, and have applied novel selection techniques to identify microorganisms that encode molecules for cold adaptation. Among our recent discoveries is that antifreeze proteins inhibit gas hydrate formation. Hydrates plug up gas lines and are a multimillion-dollar problem to the gas and oil industry and if we could produce a “green” gas hydrate inhibitor, it would be a important contribution for environmental protection.

»» No Lab Website »« email: walkervk@queensu.ca »« telephone: 613-533-6123 ««

 Some Recent Publications: 

• Kumar N, Shah V. & Walker VK (2011) Influence of a nanoparticle mixture on an arctic soil community. Environ Tox & Chem  In press
• Philbrook NA, Winn LM & Walker VK (2011) The effects of Ag and TiO2 nanoparticles on reproduction and development of Drosophila melanogaster and CD-1 mice. Toxicol & Appl Pharma In press
• Garnham C, Campbell R, Walker VK & Davies PL (2011) Novel dimeric beta-helical model of an ice nucleation protein with bridged active sites. BMC Struct Biol 11:36
• Chu H, Neufeld JD, Walker VK & Grogan P (2011) Soil bacterial, archaeal and fungal community structures among vegetation types in a low arctic tundra landscape. Soil Biol & Biochem 75:1756
• Philbrook NA, Walker VK, Afrooz  ARMN, Saleh NB  & Winn LM (2011) Investigating the effects of functionalized carbon nanotubes on reproduction and development in Drosophila melanogasterand CD-1 mice. Repro Toxicol In press
• Daraboina N, Ripmeester JA, Walker VK  & Englezos P (2011) Natural gas hydrate formation & decomposition in the presence of kinetic inhibitors I: High pressure calorimetry. Energy & Fuels 25:4392
• Daraboina N, Ripmeester JA, Walker VK & Englezos P.  (2011) Natural gas hydrate formation & decomposition in the presence of kinetic inhibitors II: Stirred microreactor experiments. Energy & Fuels 25:4384
• Daraboina N, Ripmeester JA, Walker VK & Englozos P (2011) Natural gas hydrate formation & decomposition in the presence of kinetic inhibitors III: Structural & composition changes. Energy & Fuels 25:4398
• Kumar N, Shah V & Walker VK (2011). Perturbation of an arctic soil microbial community by metal nanoparticles. J Hazardous Materials 190:816
• Lauersen KJ, Brown A, Middleton A, Davies PL & Walker VK (2011) Expression and characterization of an antifreeze protein from the perennial rye grass, Lolium perenne. Cryobiology 62:194
•  Gordienko R, Ohno H, Singh V, Jia Z, Ripmeester J & Walker VK (2010) Towards a green hydrate inhibitor: imaging antifreeze proteins on clathrates PLoS ONE .11:e8953
• Wilson S & Walker VK (2010) Selection of low-temperature resistance in bacteria and potential applications. Environ. Technol. 31:943
• Wathen B, Kwan P, Jia Z & Walker VK (2010) Modeling the interactions between poly (N-vinylpyrrolidone) and gas hydrates. HPCS 2009 High Performance Computing Systems and Applications Vol. 5976.
• Ohno H, Suslio R, Gordienko R, Ripmeester J & Walker VK (2010) Interaction of antifreeze proteins with hydrocarbon hydrates. Chemistry, European J. 16:10409
• Affleck JG, Nowickyj SM & Walker VK (2010) Selection for methotrexate resistance in mammalian cells bearing a Drosophila dihydrofolate reductase transgene. Cell Biology & Toxicity 26:117
• Yu, S.O., Middleton, A.J., Tomczak, M.M.., Walker, V.K. and Davies, P.L. (2010) Ice restructuring inhibition activities in antifreeze proteins with distinct differences in thermal hysteresis. Cryobiology 61, 327-334.