Antitumor and HIV-1 Reverse Transcriptase Inhibitory Activities of a Hemagglutinin and a Protease Inhibitor from Mini-Black Soybean

الملخص EN

Protease inhibitors (PIs) and hemagglutinins are defense proteins produced by many organisms.

From Chinese mini-black soybeans, a 17.5-kDa PI was isolated using chromatography on Q-Sepharose, SP-Sepharose, and DEAE-cellulose.

A 25-kDa hemagglutinin was purified similarly, but using Superdex 75 instead of DEAE-cellulose in the final step.

The PI inhibited trypsin and chymotrypsin (IC50 = 7.2 and 8.8 μM).

Its trypsin inhibitory activity was stable from pH 2 to pH 13 and from 0∘C to 70∘C.

The hemagglutinin activity of the hemagglutinin was stable from pH 2 to pH 13 and from 0∘C to 75∘C.

The results indicated that both PI and hemagglutinin were relatively thermostable and pH-stable.

The trypsin inhibitory activity was inhibited by dithiothreitol, signifying the importance of the disulfide bond to the activity.

The hemagglutinating activity was inhibited most potently by D (+)-raffinose and N-acetyl-D-galactosamine, suggesting that the hemagglutinin was specific for these two sugars.

Both PI and hemagglutinin inhibited HIV-1 reverse transcriptase (IC50 = 3.2 and 5.5 μM), proliferation of breast cancer cells (IC50 = 9.7 and 3.5 μM), and hepatoma cells (IC50 = 35 and 6.2 μM), with relatively high potencies.