title: Purification and characterization of a ∼43 kDa antioxidant protein with antitumor activity from Pholiota nameko.
abstract: BACKGROUND
  Pholiota nameko water-soluble protein (PNWSP), isolated from the dried fruiting bodies of Pholiota nameko, was purified by a successive chromatographic process using Q anion exchange column, SP cation exchange column and Superdex 200 gel filtration column. PNWSP was assessed for antioxidant activities in different assay systems, and the effect on cell proliferation of human breast cancer MCF7 cells was investigated.
  
  
  RESULTS
  Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analytical ultracentrifugation analysis revealed the homogeneity of PNWSP with apparent molecular weight of ∼43 kDa, and the identification was confirmed by peptide mass fingerprint analysis. It showed potential antioxidant activities in scavenging free radicals, reducing power and chelating effect on Fe(2+), and had a protective effect against DNA amage. Moreover, it inhibited the proliferation of MCF7 cells by inducing apoptosis, in which the change in cell cycle distribution and the loss of mitochondrial transmembrane potential were observed by flow cytometry.
  
  
  CONCLUSIONS
  The results showed that PNWSP could be a natural antioxidant and developed as a potential chemotherapeutic agent candidate against human breast cancer.
authors.affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Qian
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China.
authors.forename: Yeni
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Nankai University, Tianjin 300071, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Liu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000494:pharmacology*; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D001943:Breast Neoplasms / Q000188:drug therapy; D049109:Cell Proliferation / Q000187:drug effects; D005260:Female; D005638:Fruit / Q000737:chemistry; D006801:Humans; D061986:MCF-7 Cells / Q000187:drug effects; D055368:Pholiota; D008517:Phytotherapy; D010940:Plant Proteins / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D000975:Antioxidants; D010940:Plant Proteins
keywords: PNWSP; Pholiota nameko; antioxidant; antitumor; identification; purification