title: A novel thyroglobulin-binding lectin from the brown alga Hizikia fusiformis and its antioxidant activities.
abstract: A lectin (HFL) was isolated from the brown alga, Hizikia fusiformis, through ion exchange on cellulose DE52 and HPLC with a TSK-gel G4000PWXL column. SDS-PAGE showed that HFL had a molecular mass of 16.1 kDa. The HPLC (with a TSK-gel G4000PWXL column) indicated that HFL is a tetramer in its native state. The total carbohydrate content was 41%. Glucose, galactose and fucose were the monosaccharide units of HFL, and the normalized mol% values were 6, 14 and 80, respectively. HFL contains a large amount of the acidic amino acid, Asx. The β-elimination reaction suggested that the oligosaccharide and peptide moieties of HFL may belong to the N-glucosidic linkage. The amino acid sequences, of about five segments of HFL, were acquired by MALDI-TOF/TOF, and the sequences have no homology with other lectins. HFL was found to agglutinate sheep erythrocytes. The hemagglutination activity was inhibited by thyroglobulin, from bovine thyroid, but not by any of the monosaccharides tested. The lectin reaction was independent of the presence of the divalent cation Ca(2+). HFL showed free radical scavenging activity against hydroxyl, DPPH and ABTS(+) radicals.
authors: Zhejiang Provincial Key Lab for Subtropical Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China.
authors: Mingjiang
authors: M
authors: Wu
authors: College of Food Science and Engineering, Dalian Ocean University, Dalian 116023, China. Electronic address: changqingtong@dlou.edu.cn.
authors: Changqing
authors: C
authors: Tong
authors: Zhejiang Provincial Key Lab for Subtropical Water Environment and Marine Biological Resources Protection, College of Life and Environmental Science, Wenzhou University, Wenzhou 325035, China.
authors: Yue
authors: Y
authors: Wu
authors: Department of Agronomy, Hetao College, Hetao 015000, China.
authors: Shuai
authors: S
authors: Liu
authors: College of Food Science and Engineering, Dalian Ocean University, Dalian 116023, China. Electronic address: aisingioro@hotmail.com.
authors: Wei
authors: W
authors: Li
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000276:immunology; D006384:Hemagglutination; D037102:Lectins / Q000737:chemistry* / Q000302:isolation & purification; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010940:Plant Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D044647:Sargassum / Q000737:chemistry*; D012756:Sheep; D013954:Thyroglobulin / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D037102:Lectins; D010940:Plant Proteins; D013954:Thyroglobulin
keywords: Brown alga; Free radicals; Hizikia fusiformis; Lectin; Thyroglobulin from bovine thyroid