Purification and glycosylation analysis of an acidic pectin methylesterase in jelly fig (Ficus awkeotsang) achenes.
An acidic pectin methylesterase (PME) is responsible for the gelation of water extract from jelly fig (Ficus awkeotasang) achenes. A new, fast and efficient, method has been developed to purify this acidic PME. The method includes preparing jelly curd by traditional hand washing, extracting proteins from the curd, and separating PME by anion-exchanger. The purified PME exists as a monomer of 38 kDa determined by gel filtration, and exerts enzymatic activity over a broad pH range, particularly in acidic environments where most known PME enzymes from various species are inactivated. Chemical staining and enzymatic cleavage suggest that the jelly fig PME is an N-linked glycoprotein. Fluorophore-assisted carbohydrate electrophoresis reveals that the polysaccharide of this glycoprotein putatively consists of 22 hexoses including 16 mannose, 4 N-acetylglucosamine, and 2 galactose residues.
Ding
Joe L C
JL
Graduate Institute of Agricultural Biotechnology, National Chung-Hsing University, Taichung, Taiwan 40227 ROC.
Hsu
Joyce S F
JS
Wang
Miki M C
MM
Tzen
Jason T C
JT
D000117:Acetylglucosamine / Q000032:analysis; D002265:Carboxylic Ester Hydrolases / Q000302:isolation & purification* / Q000378:metabolism*; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D030681:Ficus / Q000201:enzymology*; D005690:Galactose / Q000032:analysis; D006031:Glycosylation; D006863:Hydrogen-Ion Concentration; D008358:Mannose / Q000032:analysis; D009005:Monosaccharides / Q000032:analysis; D011134:Polysaccharides / Q000032:analysis
D009005:Monosaccharides; D011134:Polysaccharides; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; D008358:Mannose; D000117:Acetylglucosamine; D005690:Galactose