+44 (0) 118 378 8446
+44 (0) 118 378 6331
School of Pharmacy,
University of Reading,
PO Box 228, Whiteknights,
Reading, RG6 6AJ,
Dr. R. J. Green joined the School of Chemistry in 2003 as a Lecturer in
Physical Chemistry and has recently moved to the new school of Pharmacy as
Lecturer in Pharmaceutics. She has established a research group in biophysical
surface chemistry. Her research concentrates on probing protein
interactions at interfaces, with applications in biomaterial research and
food/pharmaceutical colloid stabilisation.
Peptide interactions at membrane
Antimicrobial peptides act as defensive or
offensive agents by rupturing the membranes of target cells. Some
preference for bacterial cells is observed and therefore they are studied
due to their potential role as a family of antibiotics. However, their
specificity towards bacterial cells varies and the mechanism for
specificity is not clearly understood. To determine the lipid layer and
peptide characteristics that influence peptide-membrane interactions, our
research utilises a range of complementary techniques; external reflection
FTIR, surface tensiometry, atomic force microscopy and neutron
reflectivity. Using these techniques, the binding and structural changes
of the peptide to lipid monolayers at the air-liquid interface and lipid
bilayers at the solid-liquid interface is studied. The composition of the
lipid layer can be varied so as to model a variety of different cell types
and, thus, determine the physical and chemical factors that control
Protein – surfactants interactions
The study of interactions between protein and low
molecular weight surfactants has importance in several biotechnological
disciplines. For example, the protein-surfactant interaction controls
colloidal stability in foods and pharmaceutics, is made use of in
SDS-polyacrylamide electrophoresis and controls detergency efficiency.
Our research utilises isothermal titration calorimetry, FTIR spectroscopy,
surface tensiometry and neutron reflectivity to probe these interactions
and to study the formation of protein-surfactant complexes in solution and
at interfaces. Recent research has focused on the interfacial structure
of protein-surfactant complexes and the mechanism by which different
surfactants remove protein from interfaces.
Protein adsorption to biomaterials
Different interfacial chemistries, protein
structures and solution environments all influence the way in which
proteins adsorb. Surface analytical techniques, such as neutron
reflectivity and surface plasmon resonance, are used to determine how
these variables control protein adsorption. Of particular importance is a
protein’s structure at the surface of cells or in contact with synthetic
biological implants, since this often determines the function of the
protein and/or the implant. Spectroscopic techniques, such as Fourier
transform infrared spectroscopy (FTIR), can be used to determine the
changes in protein secondary structure.
1. “Unfolding and intermolecular association in globular proteins
adsorbed at interfaces” Green RJ, Hopkinson I, Jones RAL. Langmuir
1999; 15: 5102–5110.
2. “Interaction of lysozyme and sodium dodecyl sulfate at the air-liquid
interface” Green RJ, Su TJ, Joy H, Lu JR. Langmuir 2000; 16: 5797-5805.
3. “The displacement of pre-adsorbed protein with a cationic surfactant
at the SiO2-water interface” Green RJ, Su TJ, Lu JR, Penfold J
J. Phys. Chem. B 2001; 105: 9331-9338.
4. “Analysis of the SDS-lysozyme binding isotherm” Lad MD, Ledger VM,
Briggs B, Frazier RA, Green RJ Langmuir 2003; 19: 5098-5103.
5. “Probing protein-tannin interactions by isothermal titration
calorimetry” Frazier RA, Papadopoulou A, Kissoon D, Mueller-Harvey I,
Green RJ J. Agric. Food. Chem. 2003; 5151: 5189-5195