Isolation of a new trypsin inhibitor from the Faba bean (Vicia faba cv. Giza 843) with potential medicinal applications.
A new 15-kDa Bowman-Birk type trypsin inhibitor (termed VFTI-G1) was isolated from the seeds of Faba bean (Vicia faba cv. Giza 843) using cation exchange chromatography on an SP-Sepharose column, anion exchange chromatography on Q-Sepharose and Mono Q columns, and finally size exclusion chromatography on a Superdex 75 column. VFTI-G1 manifested significant antiproteolytic activity against trypsin (5761 BAEE units/mg, K(i) 20.4 × 10(-9) M), but only a slight chymotrypsin inhibitory activity (< 10 BTEE units/mg). The suitable environment to sustain its trypsin inhibitory activity was at temperatures below 60 °C and at pH 7. Its trypsin inhibitory activity was inhibited by the reducing agent dithiothreitol in a dose-dependent manner, indicating the significance of intact disulfide bonds to the trypsin inhibitory activity. It inhibited HIV-1 reverse transcriptase (RT) activity with an IC(50) of about 0.76 µM. Furthermore, VFTI-G1 showed specific antiproliferative activity toward HepG2 hepatoma cells by inducing chromatin condensation and cell apoptosis. The HIV-1 RT inhibitory activity of VFTI-G1 and its specific antiproliferative activity toward Hep G2 cells may find medical applications.
School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Evandro Fei
EF
Fang
Abdallah Abd Elazeem
AA
Hassanien
Jack Ho
JH
Wong
Clara Shui Fern
CS
Bah
Saeed Saad
SS
Soliman
Tzi Bun
TB
Ng
D000595:Amino Acid Sequence; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D045744:Cell Line, Tumor; D004534:Egypt; D054303:HIV Reverse Transcriptase / Q000737:chemistry; D006801:Humans; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry* / Q000494:pharmacology; D018894:Reverse Transcriptase Inhibitors / Q000737:chemistry; D012639:Seeds / Q000737:chemistry*; D014361:Trypsin Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D031307:Vicia faba / Q000737:chemistry*
D000970:Antineoplastic Agents; D010940:Plant Proteins; D018894:Reverse Transcriptase Inhibitors; D014361:Trypsin Inhibitors; C556147:VFTI-G1 protein, Vicia faba; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase