Primary Structures of N-Linked Oligosaccharides of Momordin-a, a Ribosome-inactivating Protein from Momordica charantia Seeds.

Abstract

The structures of the A^-linked oligosaccharides of momordin-a, which is a ribosome-inactivating protein from the seeds of Momovdicacharantia, were analyzed. First, the TV-linked oligosaccharides of this glycoprotein were liberated by hydrazinolysis. After N-acetylation, the reducing ends of the oligosaccharides were coupled with 2-aminopyridine and the pyridylamino (PA-) derivatives were purified by gel filtration and high performance liquid chromatography (HPLC) on an ODS-silica column. Three kinds of oligosaccharide fractions were separated by HPLC. The structure of each oligosaccharide isolated was analyzed by a combination of sugar component analysis, exoglycosidase digestion, another kind of HPLCusing an amide-silica column, and 500-MHz *H NMRspectroscopy. Thestructures of two mainoligosaccharides wereestablished to be:Xyl l /?2Man/J4GlcNAc/*4GlcNAc Momordin-a, which inactivates 60S ribo-

Bitter Gourd <i>(Momordica charantia)</i> Extract Activates Peroxisome Proliferator-Activated Receptors and Upregulates the Expression of the Acyl CoA Oxidase Gene in H4IIEC3 Hepatoma Cells

“…For example, seed extracts contain MAP-30, an anti-HIV and antitumor protein [24], momorcharins [32] and momordins [21], which inactivate ribosomes, and momordin Ic [25] and oleanolic acid glycoside [26], both of which can alter gastrointestinal transit time and blood glucose. In an attempt to search for the chemical constituent responsible for the hypoglycemic effect, a series of triterpene glycosides and oleanane-type triterpene saponins have been identified from Japanese bitter gourd fresh fruit, yet their biological effects have not been reported [30].…”

Salt-Adaptation of Tobacco BY2 Cells Induces Change in Glycoform ofN-Glycans: Enhancement of Exo- and Endo-Glycosidase Activities by Salt-Adaptation

“…5-2). The product was converted to Man1-4GlcNAc1-4-(Fuc1-3)GlcNAc-PA (MF) 9) by snail -1,2-xylosidase digestion (Fig. 5-3), and to Xyl1-2Man1-4Glc-NAc1-4GlcNAc-PA (MX) 9) by snail -1,3-fucosidase digestion (Fig.…”

“…Authentic PA-sugar chains were prepared as described in previous papers. [7][8][9][10] Actinase E was purchased from Kaken Seiyaku (Tokyo, Japan).…”

“…ESI-MS and MS/MS analyses of PA-oligosaccharides were done as described in our previous reports, 9,10,14) using a Perkin Elmer Sciex API-III triple-quadrupole mass spectrometer with an atmospheric-pressure ionization ion source.…”

Differential Effects of Foods Traditionally Regarded as &lsquo;Heating&rsquo; and &lsquo;Cooling&rsquo; on Prostaglandin E₂ Production by a Macrophage Cell Line

“…For example, seed extracts contain MAP-30, an anti-HIV and anti-tumor protein [28], momorcharins [43] and momordins [21], which inactivate ribosomes, and momordin Ic [30] and oleanolic acid glycoside [36], both of which can alter gastrointestinal transit time and blood glucose. An extract of bitter gourd fruit has been shown to have hypoglycemic activity [46] and to alter the activities of phase I and phase II drug metabolizing enzymes in the rat liver [25].…”