Macromolecular components of tomato fruit pectin.
Chelate and alkaline-soluble pectin extracted from cell walls of pericarp tissue from mature green, turning, and red ripe (Lycopersicon esculentum Mill.) fruit (cv. Rutgers), were studied by high-performance size-exclusion chromatography. Computer-aided curve fitting of the chromatograms to a series of Gaussian-shaped components revealed that pectin from all fractions was composed of a linear combination of five macromolecular-sized species. The relative sizes of these macromolecules as obtained from their radii of gyration were 1:2:4:8:16. Dialysis against 0.05 M NaCl induced partial dissociation of the biopolymers. Apparently, the weight fraction of smaller sized species increased at the expense of larger ones. Also, the dissociation produced low-molecular-weight fragments. Behavior in the presence of 0.05 M NaCl led to the conclusion that cell wall pectin acted as if it were an aggregated mosaic, held together at least partially through noncovalent interactions.
Fishman
M L
ML
U.S. Department of Agriculture, ARS, Eastern Regional Research Center, Philadelphia, Pennsylvania 19118.
Gross
K C
KC
Gillespie
D T
DT
Sondey
S M
SM
D002473:Cell Wall / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D003956:Dialysis; D008970:Molecular Weight; D010368:Pectins / Q000032:analysis*; D010940:Plant Proteins / Q000302:isolation & purification; D010944:Plants / Q000032:analysis*
D010940:Plant Proteins; D010368:Pectins