title: Isolation, identification and characterization of a novel antioxidant protein from the nematocyst of the jellyfish Stomolophus meleagris.
abstract: Reactive oxygen species (ROS) can damage the lipids, proteins and DNA when produced excessively in cells. Here, we describe the isolation and identification of a novel antioxidant protein named SmP90 from the nematocyst of jellyfish Stomolophus meleagris by 50% ammonium sulfate precipitation and gel filtration chromatography, superdex75. HPLC and SDS-PAGE analysis revealed >95% purity of SmP90 with apparent molecular weight of 90 kDa, approximately. The identification of SmP90 was confirmed by both N-terminal amino acids sequencing, with the sequences of NLDTPYCFYSGDYGG, and peptide mass fingerprint (PMF) analysis by MALDI-TOF-MS. However, no known protein had been completely matched in the database, which indicated that SmP90 might be a novel protein. The antioxidant assay result showed that it had strong superoxide anion radical-scavenging activity with the half-scavenging concentration (EC(50)) of about 16 μg/mL. Therefore, the present study is the first time to demonstrate a high efficient method of isolating a novel antioxidant protein from the nematocyst of jellyfish S. meleagris.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Road, Qingdao 266071, China.
authors.forename: Rongfeng
authors.initials: R
authors.lastname: Li
authors.forename: Huahua
authors.initials: H
authors.lastname: Yu
authors.forename: Ronge
authors.initials: R
authors.lastname: Xing
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.forename: Yukun
authors.initials: Y
authors.lastname: Qing
authors.forename: Kecheng
authors.initials: K
authors.lastname: Li
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.forename: Xiangtao
authors.initials: X
authors.lastname: Meng
authors.forename: Jinhui
authors.initials: J
authors.lastname: Cui
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Li
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D058894:Nematocyst / Q000737:chemistry*; D010084:Oxidation-Reduction / Q000187:drug effects; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification* / Q000494:pharmacology; D037401:Scyphozoa / Q000737:chemistry*; D013481:Superoxides / Q000737:chemistry
chemical_list: D000975:Antioxidants; D011506:Proteins; D013481:Superoxides