title: Lagenin, a novel ribosome-inactivating protein with ribonucleolytic activity from bottle gourd (Lagenaria siceraria) seeds.
abstract: The seeds of Lagenaria siceraria (Family Cucurbitaceae) were extracted with water and the extract was lyophilized. The lyophilized extract was chromatographed on a DEAE-cellulose column in 10 mM Tris-HCl buffer (pH 7.2). The unadsorbed fraction was applied to an Affi-gel Blue gel column previously equilibrated with the same buffer. After removal of unadsorbed materials, the adsorbed proteins were eluted with 1.5 M NaCl in the Tris-HCl buffer. After dialysis the adsorbed fraction was loaded on a CM-Sepharose CL-6B column which had been equilibrated with and was eluted with the same buffer. After elution of unadsorbed proteins, the column was eluted with a gradient of 0-1 M NaCl in 10 mM Tris-HCl buffer (pH 7.2). The fraction eluting at about 0.55 M NaCl, which represented pure ribosome inactivating protein (RIP), inhibited cell-free translation in a rabbit reticulocyte system with an IC50 of 0.21 nM and exerted ribonuclease activity on yeast tRNA with an activity of 45 U/mg. The RIP was designated lagenin. It possessed a molecular weight of 20 kDa, smaller than the range of 26-32 kDa reported for other RIPs. The N-terminal sequence of lagenin exhibited a lesser extent of similarity to those of other Cucurbitaceae RIPs, characterized by a deletion of the first three amino acid residues and a replacement of the 4th (Phe), 17th (Phe), 18th (Ile) and 22nd (Arg) residues which are invariant in other RIPs.
authors: Department of Microbiology, China Agricultural University, Beijing, Peoples Republic of China.
authors: H X
authors: HX
authors: Wang
authors: T B
authors: TB
authors: Ng
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002848:Chromatography, DEAE-Cellulose; D019662:Cucurbitaceae / Q000737:chemistry*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology*; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D011817:Rabbits; D012260:Ribonucleases / Q000037:antagonists & inhibitors* / Q000302:isolation & purification / Q000494:pharmacology*; D012270:Ribosomes / Q000187:drug effects*; D012639:Seeds / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D010940:Plant Proteins; D012260:Ribonucleases; C417219:lagenin