Figure 2.

Profiles of a 1% (w/v) solution of partially hydrolyzed polygalacturonic acid exposed to tomato seed protein extract indicate the activity of an exo-PG. High-pressure liquid chromatography with pulsed amperometric detection (HPLC-PAD) resulted in the fractionation of a 1% (w/v) solution of partially acid hydrolyzed polygalacturonic acid. The solution is comprised of oligomers with a degree of polymerization from 6 to 19 centered on 10 to 12 (G12 fraction; Campbell and Labavitch, 1991). A, Untreated G12; B, G12 spiked with a commercial source of mono- (1) and di-GalUA (2) (made 2.5 nm with respect to both); C, G12 after exposure to tomato seed extract; D, G12 exposed to boiled tomato seed extract; E, G12 exposed to tomato seed extract containing 50 mm EDTA; F, G12 exposed to a commercial source of endo-PG from A. niger. Extracts in chromatograms C to E contained 5 mm CaCl₂. Response bars to the left of each chromatogram represent a 100-mV deflection.