Structural Proteins of the Primary Cell Wall: Extraction, Purification, and Analysis

Structural proteins of the primary cell wall present unusual but interesting problems for structural biologists in particular and plant biologists in general. As structure is the key to function; then the biochemical isolation of these glycoproteins for further study is paramount. Here, we detail the “classical” method for isolating soluble extensin monomers by elution of monomeric precursors to network extensin from tissue cultures. We also outline an additional approach involving genetic engineering that can potentially yield the complete genomic range of extensins and other hydroxyproline-rich glycoprotein (HRGPs) currently underutilized for biotechnology.