Biophysics

Members of the Biophysics Department are researching the physics of life in several different areas, usually in close collaboration with biologists and sometimes with industrial partners.

Protein Structure Group
Plant Membrane Biophysics Group
Bioimpedance
Cryobiology and Anhydrobiology
Bioacoustics


Protein Structure Group

This group determines the structure of important proteins. To produce the required quantities of high quality protein, all the tools of recombinant DNA technology are used. We have recently determined the structures of two proteins.

  • PA12 controls remodelling processes in mammals by undergoing a dramatic structural change: We now have high resolution structures of the "before " and "after" states.
  • PE545 is a static, quantum mechanical machine involved in photosynthesis, and which ensures high quantum yield for photon capture.

We are currently hunting the structure of a human chloride ion channel protein- NCC27.

Several projects are still at the cloning stage, using bacteria to produce foreign proteins from their genes. We aim to understand the physical mechanism of several "chaperones": proteins that assist other proteins to adopt their correct three-dimensional structure.

We are investigating the physical basis for fundamental asymmetries in proteins and are examining beta-structures at ultra high resolution. We have also recently devised a novel enzyme mechanism for rubisco-the world's most abundant enzyme. This mechanism is based on electrostatic transitions and is likely to have general implications for a large class of enzymes.

Plant Membrane Biophysics Group

This group studies transport systems in plant cell membranes and their role in salt tolerance. The electrical characteristics of single living cells are measured by voltage clamping giant-celled charophytes (models for higher plants) and Ventricaria (marine algae). Single channels are characterised by patch clamp technique. Ions responsible for various currents are identified using vibrating, ion-sensitive electrodes.

Bioimpedance

This group studies the electrical impedance and concentration changes associated with the flow of electrical current through electrodes, electrolytes and membranes. Current projects include characterisation of the depletion layer that can form between artificial membranes containing fixed charges of opposite sign, and examination of the concentration changes that can occur around implanted neural electrodes.

Cryobiology and Anhydrobiology

Cryobiology and Anhydrobiology In collaboration with biologists and physicists from other universities, we study the damage produced by freezing and drying in cells and tissues .

In collaboration with biologists and physicists from other universities, we study the damage produced by freezing and drying in cells and tissues. One area is the cellular effects of freezing and cryopreservation . Another is the environmental influences on frost in alpine forests.

Bioacoustics

Two academic staff members are jointly in the Biophysics Department and theAcoustics Group. They research the acoustics of the vocal tract and some aspects of cochlear implants (see under Applied Physics).

Academic Staff and Research Fields

Dr. Mary J. Beilby BSc. PhD. UNSW, MAIP, Grad. Cert. H. Ed.
I study electrical properties of membranes surrounding living plant cells. Potential difference (p. d.) across the membrane can be measured and controlled.The ionic currents flowing through a multitude of specific transport systems (protein molecules imbedded in the lipid bilayer) show characteristic p.d. dependencies. Such current-voltage curves allow characterisation and modelling of different transporters. My new project investigates the role some of these transporters play in the cell response to varying salinity of the environment. The experiments are performed on giant-celled algae characeae (single cells up to 1 mm in diameter and several cm in length), which allow extensive manipulation on the single cell level.
Professor Paul M. G. Curmi BSc. PhD. Sydney
My research is aimed at understanding life processes at a molecular level. Our main focus is on the structure and function of proteins, in particular, those that act as molecular machines. My group uses an array of techniques, especially: x-ray crystallography, recombinant DNA technology, protein chemistry, biophysics and bioinformatics. Current projects include: the CLIC chloride ion channels, serpins, RNPs, light-harvesting proteins, tumour suppressors, archaeal evolution and protein structural transitions.

Associate Professor John Smith BSc. Sydney, PhD. UNSW
My research interests are focussed on studying various electrodiffusion problems that involve determining how ions move through materials under the influence of gradients in electric potential and concentration. This has led to the detection of the depletion layer that can form between artificial membranes containing fixed charges of opposite sign. The concentration changes that can occur around implanted neural electrodes or plant cells are also under investigation.

Dr. Krystyna E. Wilk MSc. Cracow PhD. UNSW MAIP
Following my interest in the light harvesting proteins I became interested in how the proteins are targeted to the membranes and how they are inserted or translocated across membranes. For this project I will continue towards the structure determination of light harvesting membrane proteins using X-ray crystallography methods.
Professor Joe Wolfe BSc. Qld, BA. UNSW, PhD. ANU.
My main research in biophysics is in thermal physics, with particular application to the damage produced by freezing and/or desiccation. I collaborate with biophysicists, physiologists and ecologists on problems including the ultrastructural damage produced by the large anisotropic stresses induced by freezing and/or dehydration and the analysis of heat exchange and ice nucleation. I also work on bioacoustics, which is listed under acoustics in the Department of Environmental and Applied Physics.