1. Alltech European Biosciences Research Centre, The National University of Ireland, Galway, Republic of Ireland; Cell and Molecular Biology Group, Department of Biochemistry, University College Galway, Galway, Republic of Ireland; Department of Biological Sciences, California State Polytechnic University, Pomona, California 91768-4032; Department of Chemistry, University College, Galway, Republic of Ireland; and School of Chemical Sciences, Dublin City University, Glasnevin, Dublin 9, Republic of Ireland