Research Guides

My research combines experimental and theoretical approaches to probe the structural and dynamical properties of proteins, both in their native folded form and in non-native partly folded, misfolded and denatured states. The study of non-native protein conformations is challenging, as these states are often highly flexible systems in which multiple conformers are being adopted. Non-native protein conformations are of increasing interest because of their relevance to understanding protein stability, folding, misfolding and aggregation. Protein misfolding has particular importance with respect to disease states such as Alzheimer's disease, Parkinson's disease and bovine spongiform encephalopathy (BSE).

The work particularly uses high-resolution NMR techniques and molecular dynamics simulations. Models from the MD simulations provide a framework for interpreting experimental data while the experimental work helps prompt new theoretical developments.  Systems we are currently studying include alpha-lactalbumin, lysozyme, lipid transfer proteins, a b-type variant of cytochrome c₅₅₂, mouse major urinary protein, nitroreductase, a variety of heme binding proteins and peptides composed of beta-amino acids. 

 Current projects include characterising the disulphide bond shuffling seen in alpha-lactalbumin and lipid transfer proteins on prolonged heating, using residual dipolar coupling constants to study non-native states of alpha-lactalbumin, understanding the promiscuity of ligand binding to mouse major urinary protein, characterising the heme binding sites in a data base of heme binding proteins and modeling the conformational preferences of beta-peptides.

Heat treatment of bovine alpha-lactalbumin results in partially-folded, disulfide bond shuffled states with enhanced surface activity. R. Wijesinha-Bettoni, C. Gao, J.A. Jenkins, A. Mackie, P.J. Wilde, E.N.C. Mills and L.J. Smith  Biochemistry 2007, 46, 9774-9784.

Post-translational modification of barley LTP1b: the lipid adduct lies in the hydrophobic cavity and alters the protein dynamics. R. Wijesinha-Bettoni, C. Gao, J.A. Jenkins, A. Mackie, P.J. Wilde, E.N.C. Mills and L.J. Smith FEBS Letters 2007, 581, 4557-4561.

Surface properties are highly sensitive to small pH induced changes in the 3-D structure of alpha-lactalbumin. C. Gao, R. Wijesinha-Bettoni, P.J. Wilde, E.N.C. Mills, L.J. Smith and A.R. Mackie. Biochemistry 2008, 47, 1659-1666.

Disulfide bond shuffling in bovine alpha-lactalbumin: MD simulation confirms experiment. N. Schmid, C. Bolliger, L.J. Smith and W.F. van Gunsteren Biochemistry 2008, 47, 12104-12107.

Probing the urea dependence of residual structure in denatured human alpha-lactalbumin. V. A. Higman, H. I. Rösner, R. Ugolini, L. H. Greene, C. Redfield and L. J. Smith J. Biomol. NMR 2009, 45, 121-131.

Partially folded forms of barley lipid transfer protein are more surface active. E. N. C. Mills, C. Gao, P. J. Wilde, N. M. Rigby, R. Wijesinha-Bettoni, V. E. Johnson, L. J. Smith and A. R. Mackie Biochemistry 2009, 48, 12081-12088.

The binding cavity of mouse major urinary protein is optimised for a variety of ligand binding modes. T. A. Pertinhez, E. Ferrari, E. Casali, J. A. Patel, A. Spisni and L. J. Smith Biochem. Biophys. Res. Comm. 2009, 390, 1266-1271.

The structural characteristics of non-specific lipid transfer protein explain their resistance to gastroduodenal proteolysis. R. Wijesinha-Bettoni, Y. Alexeev, P. Johnson, J. Marsh, A. I. Sancho, S. U. Abdullah, A. R. Mackie, P. R. Shewry, L. J. Smith, E. N. C. Mills Biochemistry 2010, 49, 2130-2139.

Heme proteins - diversity in structural characteristics, function and folding. L. J. Smith, A. Kahraman and J. M. Thornton  Proteins: Structure, Function and Bioinformatics 2010, 78, 2349-2368.