title: Purification and characterization of Luffin P1, a ribosome-inactivating peptide from the seeds of Luffa cylindrica.
abstract: A peptide designated Luffin P1 was purified from the seeds of Luffa cylindrica. Its molecular mass was determined to be 5226.1 Da by MALDI-TOF MS analysis. The purified Luffin P1 shows a strong inhibitory activity on protein synthesis in the cell-free rabbit reticulocyte lysate with IC(50) of 0.88 nM. Its reaction mechanism is the same as that of the ribosome-inactivating protein trichosanthin, which is an rRNA N-glycosidase. Besides, the results of gel filtration chromatography suggested the existence of polymers of Luffin P1 and polymerization of Luffin P1 enhanced its rRNA N-glycosidase activity. Luffin P1 was the smallest peptide yet reported that has translational inhibitory activity. The cDNA and deduced amino acid sequence of Luffin P1 has also been determined.
authors.affiliation: Key laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yue-yang Road, Shanghai 200031, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.forename: Xin-xiu
authors.initials: XX
authors.lastname: Yang
authors.forename: Hen-chuan
authors.initials: HC
authors.lastname: Xia
authors.forename: Rong
authors.initials: R
authors.lastname: Zeng
authors.forename: Wei-guo
authors.initials: WG
authors.lastname: Hu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Li
authors.forename: Zu-chuan
authors.initials: ZC
authors.lastname: Zhang
mesh_terms: D000595:Amino Acid Sequence; D002474:Cell-Free System; D018076:DNA, Complementary / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D029776:Luffa / Q000737:chemistry*; D008970:Molecular Weight; D009699:N-Glycosyl Hydrolases / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology*; D014176:Protein Biosynthesis / Q000187:drug effects*; D054788:Ribosome Inactivating Proteins; D012270:Ribosomes / Q000187:drug effects* / Q000378:metabolism; D012639:Seeds / Q000737:chemistry*
chemical_list: D018076:DNA, Complementary; D010940:Plant Proteins; D009699:N-Glycosyl Hydrolases; D054788:Ribosome Inactivating Proteins