Chemistry and Biochemistry
Biochemistry Research Facility 110
Education: Ph.D. Michigan State University
Research Interest: The hydroxyproline-rich structural glycoproteins of the plant cell wall: structure, function, and glycoprotein design
Plants are the planet's primary producers of food, fuel, materials and medicines. Therefore, a self-sustaining civilization must of necessity acquire a profound understanding of plants. My research program deals with plant cell walls, particularly their hydroxyproline-rich glycoproteins (HRGPs), which are major scaffolding components, and their role in plant form and function. And, as a result of our recent successes in creating synthetic gene analogs of HRGPs, this research also emphasizes the utilitarian value of reengineering HRGPs like plant gums or HGRP-human protein chimeras.
Plant HRGPs are modular structural glycoproteins -- generally elongated, flexible, rodlike molecules with marked peptide periodicity. Some become crosslinked to form covalent cell wall networks that control extension growth, increase the tensile strength of the cell wall and impart mechanical resistance to attack by plant pathogens. Other HRGPs such as the arabinogalactan-proteins (AGPs) remain uncrosslinked and form a protective hydrophilic cushion at the interface between the plasma membrane and cell wall. Yet others, like the gum arabic glycoprotein are protective exudate gum components, acting as plastic sealants at the sites of mechanical injury. Still other HRGPs contain highly symmetrical motifs with palindromic amino acid sidechains ñ the sequence of the amino acid sidechains reads the same forwards as backwards. Involvement of these peptide palindromes in more subtle molecular roles such as self-ordering liquid crystals could lead to biomineralization, epitaxial growth and self-assembly of wall components at the cell surface, or molecular recognition of pathogens.