Title:A Hemagglutinin from Northeast Red Beans with Immunomodulatory Activity and Anti-proliferative and Apoptosis-inducing Activities Toward Tumor Cells
Volume: 20
Issue: 10
Author(s): Yau Sang Chan, Jack Ho Wong, Evandro Fei Fang, Wenliang Pan and Tzi Bun Ng
Affiliation:
Keywords:
Bean, hemagglutinin, isolation, immunomodulatory, anti-proliferative, apoptosis-inducing.
Abstract: A 64-kDa hemagglutinin from a Phaseolus vulgaris cultivar, the northeast red bean, was purified by a protocol
composed of three chromatographic steps involving affinity chromatography on Affi-gel blue gel, cation exchange chromatography
on SP-Sepharose and FPLC-gel filtration on Superdex 75. The purified hemagglutinin appeared as a single
32-kDa band in SDS-PAGE indicating its dimeric nature. The N-terminal amino acid sequence of the hemagglutinin resembled
the sequences of lectins and hemagglutinins from a number of Phaseolus species. The hemagglutinin manifested
moderate thermostability and pH stability. It retained full activity up to 65 °C and in the pH range 2 – 12. It did not interact
with simple sugars such as glucose, mannose and galactose. The hemagglutinin exerted immunostimulatory effects by
upregulating the expression of cytokines like interferon-γ and tumor necrosis factor-α. It also exhibited antiproliferative
activity on a number of tumor cells including MCF7 (breast cancer), HepG2 (liver cancer), CNE1 and CNE2 (nasopharyngeal
cancer) cells, with stronger activity toward MCF7 and CNE1 cells. The hemagglutinin induced phophatidylserine
externalization, mitochondrial depolarization and DNA condensation in MCF7 cells, indicating initiation of apoptosis.
However, at high hemagglutinin concentrations, severe damage to the MCF7 cells was detected.