title: A protein with antiproliferative, antifungal and HIV-1 reverse transcriptase inhibitory activities from caper (Capparis spinosa) seeds.
abstract: A protein exhibiting an N-terminal amino acid sequence with some similarity to imidazoleglycerol phosphate synthase was purified from fresh Capparis spinosa melon seeds. The purification protocol entailed anion exchange chromatography on DEAE-cellulose, cation exchange chromatography on SP-Sepharose, and finally gel filtration by fast protein liquid chromatography on Superdex 75. The protein was adsorbed using 20 mM Tris-HCl buffer (pH 7.4) and desorbed using 1 M NaCl in the starting buffer from the DEAE-cellulose column and SP-Sepharose column. The protein demonstrated a molecular mass of 38 kDa in gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis, indicating that it was monomeric. The protein inhibited proliferation of hepatoma HepG2 cells, colon cancer HT29 cells and breast cancer MCF-7 cells with an IC(50) of about 1, 40 and 60 microM, respectively. It inhibited HIV-1 reverse transcriptase with IC(50) of 0.23 microM. It inhibited mycelial growth in the fungus, Valsa mali. It did not exhibit hemagglutinating, ribonuclease, mitogenic or protease inhibitory activities.
authors.affiliation: Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China. lamszekwan@yahoo.com.hk
authors.forename: Sze-Kwan
authors.initials: SK
authors.lastname: Lam
authors.forename: Tzi-Bun
authors.initials: TB
authors.lastname: Ng
mesh_terms: D000935:Antifungal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000188:drug therapy; D031484:Capparis; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D003110:Colonic Neoplasms / Q000188:drug therapy; D005658:Fungi / Q000254:growth & development; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors*; D015497:HIV-1 / Q000187:drug effects; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D018894:Reverse Transcriptase Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D012639:Seeds
chemical_list: D000935:Antifungal Agents; D000972:Antineoplastic Agents, Phytogenic; D010940:Plant Proteins; D018894:Reverse Transcriptase Inhibitors; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase