Hutchinson, AT, Malik, A, Berkahn, MB, Agostino, M, To, J, Tacchi, JL, Djordjevic, SP, Turnbull, L, Whitchurch, CB, Edmundson, AB, Jones, PM, Raison, RL & Ramsland, PA 2013, 'Formation of Assemblies on Cell Membranes by Secreted Proteins: Molecular Studies of Free Lambda Light Chain Aggregates Found on the Surface of Myeloma Cells.', Biochemical Journal, vol. 454, no. 3, pp. 479-489.View/Download from: UTS OPUS or Publisher's site
We have described the presence of cell membrane-associated ? free immunoglobulin light chains (FLC) on the surface of myeloma cells. Notably, the anti-?FLC mAb, MDX-1097, is being assessed in clinical trials as a therapy for ? light chain isotype multiple myeloma. Despite the clinical potential of anti-FLC mAbs, there have been limited studies on characterizing membrane-associated FLCs at a molecular level. Furthermore, it is not known if ?FLCs can associate with cell membranes of myeloma cells. In this study, we describe the presence of ?FLCs on the surface of myeloma cells. We found that cell surface-associated ?FLC are bound directly to the membrane and in an aggregated form. Subsequently, membrane interaction studies revealed that ?FLCs interact with saturated zwitterionic lipids such as phosphatidylcholine and phosphatidylethanolamine, and using automated docking, we characterize a potential recognition site for these lipids. Atomic force microscopy confirmed that membrane-associated ?FLCs are aggregated. Given our findings, we propose a model whereby individual FLCs show modest affinity for zwitterionic lipids, with aggregation stabilizing the interaction due to multivalency. Notably, this is the first study to image FLCs bound to phospholipids and provides important insights into the possible mechanisms of membrane association by this unique myeloma surface antigen.
Thomas, P, Stuart, BH, McGowan, NM, Guerbois, JL, Berkahn, MB & Daniel, V 2011, 'A study of ochres from an Australian aboriginal bark painting using thermal methods', Journal Of Thermal Analysis And Calorimetry, vol. 104, no. 2, pp. 507-513.View/Download from: UTS OPUS or Publisher's site
The potential of thermogravimetric analysis (TG) as a tool for the characterisation of ochre paint used in indigenous Australian bark paintings has been investigated. TG has been combined with differential scanning calorimetry (DSC) and mass spectrometry
Valenzuela, S, Berkahn, MB, Porkovich, A, Huynh, TG, Goyette, J, Martin, DK & Geczy, CL 2011, 'Soluble structure of CLIC and S100 proteins investigated by atomic force microscopy', Journal of Biomaterials and Nanobiotechnology, vol. 2, pp. 8-17.View/Download from: UTS OPUS or Publisher's site
The ability to visualise proteins in their native environment and discern information regarding stoichiometry is of critical importance when studying protein interactions and function. We have used liquid cell atomic force microscopy (AFM) to visualise proteins in their native state in buffer and have determined their molecular volumes. The human proteins S100A8, S100A9, S100A12 and CLIC1 were used in this investigation. The effect of oxidation on the protein structure of CLIC1 was also investigated and we found that CLIC1 multimerisation could be discerned by AFM, which supports similar findings by other methods. We have found good correlation between the molecular volumes measured by AFM and the calculated volumes of the individual proteins. This method allows for the study of single soluble proteins under physiological conditions and could potentially be extended to study the structure of these proteins when located within a membrane environment.
Islam, H, Wuhrer, R, Berkahn, MB, Cornell, BA, Valenzuela, S & Martin, DK 2008, 'Nanostructured TiN Thin films suitable for medical applications', Materials forum, vol. 32, pp. 129-136.View/Download from: UTS OPUS
Titanium nitride thin films are widely used in biomedical implants because of thier biocompatibility, good mechanical properties and high corrosion resistance. Titanium nitride (TiN) thin films on silicon and glass substrates were prepared using a dc megnetron sputtering system under condition of systematically varying the nitrogen pressure and titanium megnetron power.
Stuart, BH, Notter, SJ, Langlois, NE, Maynard, PJ, Ray, AS & Berkahn, MB 2007, 'Characterization of the triacylglycerol crystal formation in adipose tissue during a vehicle collision', Journal Of Forensic Sciences, vol. 52, no. 4, pp. 938-942.View/Download from: UTS OPUS or Publisher's site
The unusual appearance of crystalline fat structures was observed during the postmortem examination of a motor vehicle accident victim. The crystal structures were characterized using Fourier transform infrared spectroscopy and x-ray diffractometry. The
Nano- and submicron-structured aluminium was produced by equal channel angular extrusion with a total strain of similar to 17. Large residual stress and strain energy were built up in the extruded metal and subsequent heat treatments were applied to inve
Bai, H, Berkahn, MB & Cortie, MB 2007, 'Characterization of nanometer-sized VO2 nanoparticles prepared by an aqueous route', Proceedings of the 31st Annual Condensed Matter and Materials Meeting, Annual Condensed Matter and Materials Meeting, Australian Institute of Physics, Wagga Wagga, Australia, pp. 1-3.View/Download from: UTS OPUS
We describe a convenient aqueous route to prepare VO2, based on the reductive precipitation of vanadium dioxide VO2 from a vanadate solution. The effect of the reaction conditions is systematically studied, and a protocol to optimize the production of VO2 while minimizing the appearance of other compounds is presented. The products were characterized using calorimetry, X-ray diffraction and high-resolution scanning electron microscopy.
Valenzuela, S, Berkahn, MB, Martin, DK, Huynh, T, Yang, Z & Geczy, CL 2005, 'Elucidating the structure and function of S100 proteins in membranes - art. no. 603619', Biomems And Nanotechnology Ii, Conference on BioMEMS and Nanotechnology II, Spie-Int Society Optical Engineering, Brisbane, AUSTRALIA, pp. 3619-3619.View/Download from: UTS OPUS
100 proteins are important Ca2+-binding proteins involved in vital cellular functions including the modulation of cell growth, migration and differentiation, regulation of intracellular signal transduction/phosphorylation pathways, energy metabolism, cyt