Malcolm O’Neill received his graduate training in biochemistry at Trent Polytechnic (Nottingham, England). In 1977, he joined the group of Robert Selvendran at the Food Research Institute (FRI, Norwich, England) where he worked on the structures of polysaccharides and proteoglycans present in the cell walls of fruits and vegetables. Whilst at the FRI, he also collaborated with Vic Morris on the structure and properties of pectins and several microbial polysaccharides. Malcolm joined the Complex Carbohydrate Research Center in 1985, shortly after the group of Peter Albersheim and Alan Darvill had arrived in Athens from Colorado. Malcolm is now an Associate Research Scientist.
Malcolm’s research is focused on the structure and function of plant cell wall polysaccharides. This research involves the use of advanced analytical techniques including mass spectrometry, NMR spectroscopy and high-performance liquid chromatography.The current target of his research is the structurally complex pectic polysaccharide referred to as rhamnogalacturonan II (RG-II). RG-II exists as a borate cross-linked dimer in the cell walls of all vascular plants. Plants unable to form this cross-link have cell walls with abnormal biomechanical and biochemical properties, which severely impacts their growth and productivity.
Our goals are to (i) understand how the structure of RG-II contributes to its site-specific interaction with borate, (ii) determine how borate cross-linking of RG-II contributes to the properties and functions of the plant cell wall and (iii) establish why the cross link is required for normal plant growth and development. To this end, we are producing a collection of structurally defined natural and enzymically-generated RG-II glycoforms that differ in their ability to form the borate cross linked dimer. The experimental data obtained with these glycoforms is used by our collaborators Mike Crowley and Vivek Bharadwaj (National Renewable Energy Laboratory, Colorado) to aid and validate their molecular dynamics and quantum mechanical simulations of the RG-II monomer and dimer.