title: Primary structure and chain conformation of fucoidan extracted from sea cucumber Holothuria tubulosa.
abstract: Knowledge of the structure of polysaccharides is essential for understanding and controlling their functional properties. In this study, fucoidan was extracted from Holothuria tubulosa, a species of sea cucumber that has recently become commercially important. The primary structure of the H. tubulosa fucoidan was clarified using a combination of enzymatic degradation, methylation analysis, and NMR, and its chain conformation was further elucidated by utilizing high performance size exclusion chromatography combined with multiple angle laser light scattering and viscometry. The fucoidan was composed of a tetrafucose repeating unit [ → 3-α-L-Fucp2(OSO3(-))-1 → 3-α-L-Fucp2,4(OSO3(-))-1 → 3-α-L-Fucp-1 → 3-α-L-Fucp2(OSO3(-))-1 → ]. Its sulfate content was determined to be 31.2 ± 1.6% and the weight-average molecular mass was 1567.6 ± 34.1 kDa. The molecule adapted a random coil conformation in 0.15M NaCl solution (pH 7.4) at 25 °C, with a root-mean-square radius of 63.9 ± 1.8 nm and a hydrodynamic radius of 44.5 ± 4.5 nm. This is the first report on the chain conformation of sea cucumber fucoidan.
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; Department of Food Science, University of Massachusetts, 100 Holdsworth Way, Amherst, MA 01003, USA. Electronic address: changyg@ouc.edu.cn.
authors.forename: Yaoguang
authors.initials: Y
authors.lastname: Chang
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: ARC Centre of Excellence in Plant Cell Walls, School of Chemical Engineering, University of Queensland, Brisbane 4072, Australia.
authors.forename: Long
authors.initials: L
authors.lastname: Yu
authors.affiliation: Department of Food Science, University of Massachusetts, 100 Holdsworth Way, Amherst, MA 01003, USA; Department of Biochemistry, Faculty of Science, King Abdulaziz University, P.O. Box 80203, Jeddah 21589, Saudi Arabia.
authors.forename: David Julian
authors.initials: DJ
authors.lastname: McClements
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Xiaoqi
authors.initials: X
authors.lastname: Xu
authors.affiliation: Department of Molecular Engineering, Kyoto Institute of Technology, Kyoto 606-8585, Japan.
authors.forename: Guanchen
authors.initials: G
authors.lastname: Liu
authors.affiliation: College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D047332:Holothuria / Q000737:chemistry*; D008969:Molecular Sequence Data; D011134:Polysaccharides / Q000737:chemistry* / Q000302:isolation & purification*
chemical_list: D011134:Polysaccharides; C007789:fucoidan
keywords: Conformation; Fucoidan; Holothuria tubulosa; Primary structure; Sea cucumber