Complete amino acid sequences of three proteinase inhibitors from white sword bean (Canavalia gladiata)

Edible Sword Bean Extract Induces Apoptosis in Cancer Cells In Vitro and Inhibits Ascites and Solid Tumor Development In Vivo

Antitumor potential of edible sword bean (Canavalia gladiata (L.)) extract has been evaluated against Daltons lymphoma ascites (DLA) using in vitro and in vivo studies. Methanolic extraction was carried out and in vitro studies were performed against both DLA and A549, lung cancer cell lines. The results revealed that sword bean extract inhibited cell growth and induced apoptosis as evidenced by cytotoxic assay, Hoechst 33342 staining and acridine orange/ethidium bromide dual staining. In vivo studies performed on DLA induced solid as well as ascitic tumors models showed administration of sword bean extract (10 mg/kg B.wt.) could significantly inhibit ascitic and solid tumor development in mice. Therefore, our overall results revealed that C. gladiata treatment could significantly inhibit tumor development and induce apoptosis in tumor cells.

Effect of Ethanol Extract of Canavalia gladiata on Endurance Swimming Capacity in Mice

The effects of Canavalia gladiata ethanolic extract on endurance swimming capacity were evaluated in a mouse model. The mice were orally administered distilled water (CON), hot water extract (CGW), or 80% ethanol extract (CGE). The swimming time to exhaustion was significantly prolonged in the CGE group. Of the three groups, the CGE showed the lowest blood lactate and the highest nonesterified fatty acid and muscle glycogen levels. These results suggest that the administration of CGE could improve endurance swimming capacity by enhancing lipid catabolism and thereby preserving glycogen stores.

Precipitation of sword bean proteins by heating and addition of magnesium chloride in a crude extract

Sword bean (Canavalia gladiata) seeds are a traditional food in Asian countries. In this study, we aimed to determine the optimal methods for the precipitation of sword bean proteins useful for the food development. The soaking time for sword beans was determined by comparing it with that for soybeans. Sword bean proteins were extracted from dried seeds in distilled water using novel methods. We found that most proteins could be precipitated by heating the extract at more than 90 °C. Interestingly, adding magnesium chloride to the extract at lower temperatures induced specific precipitation of a single protein with a molecular weight of approximately 48 kDa. The molecular weight and N-terminal sequence of the precipitated protein was identical to that of canavalin. These data suggested that canavalin was precipitated by the addition of magnesium chloride to the extract. Our results provide important insights into the production of processed foods from sword bean.

Isolation and characterization of a Kunitz-type trypsin inhibitor with antiproliferative activity from Gymnocladus chinensis (Yunnan bean) seeds

A 20-kDa Kunitz-type trypsin inhibitor was isolated from Gymnocladus chinensis (Yunnan bean) seeds. The isolation procedure involved ion exchange chromatography on diethylaminoethyl cellulose (DEAE-cellulose), affinity chromatography on Affi-gel blue gel, ion exchange chromatography on sulfopropyl sepharose (SP-sepharose), and gel filtration by FPLC on Superdex 75. The trypsin inhibitor was adsorbed on DEAE-cellulose, unadsorbed on Affi-gel blue gel, and adsorbed on SP-Sepharose. It dose-dependently inhibited trypsin with an IC₅₀ value of 0.4 μM. Dithiothreitol reduced its trypsin inhibitory activity, suggesting that an intact disulfide bond is indispensable to the activity. It suppressed [methyl-³H] thymidine incorporation by leukemia L1210 cells and lymphoma MBL2 cells with an IC₅₀ value of 4.7 and 9.4 μM, respectively. There was no effect on human immunodeficiency virus⁴-1 reverse transcriptase activity and fungal growth when the trypsin inhibitor was tested up to 100 μM.

Trypsin isoinhibitors with antiproliferative activity toward leukemia cells from Phaseolus vulgaris cv "White Cloud Bean"

A purification protocol that comprised ion exchange chromatography on DEAE-cellulose, affinity chromatography on Affi-gel blue gel, ion exchange chromatography on SP-Sepharose, and gel filtration by FPLC on Superdex 75 was complied to isolate two trypsin inhibitors from Phaseolus vulgaris cv “White Cloud Bean”. Both trypsin inhibitors exhibited a molecular mass of 16 kDa and reduced the activity of trypsin with an IC₅₀ value of about 0.6 μM. Dithiothreitol attenuated the trypsin inhibitory activity, signifying that an intact disulfide bond is indispensable to the activity. [Methyl-³H] thymidine incorporation by leukemia L1210 cells was inhibited with an IC₅₀ value of 28.8 μM and 21.5 μM, respectively. They were lacking in activity toward lymphoma MBL2 cells and inhibitory effect on HIV-1 reverse transcriptase and fungal growth when tested up to 100 μM.

A Bowman-Birk trypsin inhibitor with antiproliferative activity from Hokkaido large black soybeans

A trypsin inhibitor, with an N-terminal sequence highly homologous to those of 8-kDa Bowman-Birk trypsin inhibitors, was isolated from the seeds of Hokkaido large black soybeans. The trypsin inhibitor was unadsorbed on SP-Sepharose but adsorbed on DEAE-cellulose and Mono Q. It inhibited proliferation in breast cancer (MCF-7) cells and hepatoma (Hep G2) cells with an IC50 of 35 and 140 microM, respectively. The trypsin inhibitory activity of the inhibitor was completely preserved after exposure to temperatures up to 100 degrees C for 30 min and to the pH range 2-13 for the same duration. The trypsin inhibitor inhibited HIV-1 reverse transcriptase with an IC50 of 38 microM, but was devoid of antifungal activity toward Fusarium oxysporum and Mycosphaerella arachidicola.

Purification and characterization of extracellular cysteine protease inhibitor, ECPI-2, from Chlorella sp

An extracellular cysteine protease inhibitor (ECPI-2) was purified to homogeneity from the culture filtrate of Chlorella sp. 4533 by the combination of various column chromatographies. The molecular mass of the inhibitor was estimated to be 340 kDa by SDS-PAGE. The inhibitor was extremely heat-stable under acidic or neutral condition. ECPI-2 exhibited an inhibitory activity against the proteolytic activity of papain, ficin, or chymopapain, but not against stem bromelain or cathepsin B. The inhibitor showed no inhibitory activity against trypsin, alpha-chymotrypsin or thermolysin. ECPI-2 contains 33.6% carbohydrate residues by weight and inhibits papain at a molar ratio of 1:2. The proteolysis of the inhibitor by trypsin or alpha-chymotrypsin was apparent, but the inhibitory activity of ECPI-2 was unaffected by these enzymes. The alpha-chymotrypsin hydrolysis product from ECPI-2 was further separated into six fractions by gel filtration. From these results, it is suggested that ECPI-2 has several reactive sites for papain.

Purification and primary structure determination of two Bowman-Birk type trypsin isoinhibitors from Cratylia mollis seeds

Two Bowman-Birk type trypsin inhibitors (CmTI(1) and CmTI(2)) were purified from Cratylia mollis seeds by acetone precipitation, ion exchange, gel filtration and reverse-phase chromatography. CmTI(1) and CmTI(2), with 77 and 78 amino acid residues, respectively, were sequenced in their entirety and show a high structural similarity to Bowman-Birk inhibitors from other Leguminosae. The putative reactive sites of CmTI(1) are a lysine residue at position 22 and a tyrosine residue at position 49. Different reactive sites, as identified by their alignment with related inhibitors, were found for CmTI(2): lysine at position 22 and leucine at position 49. The dissociation constant K(i) of the complex with trypsin is 1.4 nM. The apparent molecular mass is 17 kDa without DDT and 11 kDa with reducing agent and heating.