Kiwi and kaki fruit were purchased from local markets. Trypsin was
from Boehringer; bovine serum albumin, dithiothreitol, Tris, bis-Tris,
and 4-vinylpyridine were from Sigma; MES was from ICN; citrus pectin
(60% degree of methylation) was from Fluka; and DEAE-cellulose (type
DE52) was from Whatman. SDS-PAGE reagents were from BioRad.
All other reagents were of the highest commercially available quality.
Protein concentrations were determined by the BIO-RAD Protein
Assay (Bio-Rad), using bovine serum albumin as standard. SDSpolyacrylamide
gel electrophoresis (SDS-PAGE) was performed on
12.5% gels. Isoelectrofocusing was carried out with a PhastGel
apparatus (Pharmacia), in the pH range 3-9, according to the
manufacturer’s instructions.