title: Purification and characterisation of a natural lectin from the serum of the shrimp Litopenaeus vannamei.
abstract: A natural lectin from the serum of the shrimp Litopenaeus vannamei was purified to homogeneity by a single-step affinity chromatography using fetuin-coupled agarose. The purified serum lectin (named LVL) showed a strong affinity for human A/B/O erythrocytes (RBC), mouse RBC, chicken RBC and its haemagglutinating (HA) activity was specifically dependent on Ca2+ and reversibly sensitive to EDTA. LVL inactive form had a molecular mass estimate of 172 kDa and was composed of two non-identical subunits (32 and 38 kDa) cross-linked by interchain disulphide bonds. Significant LVL activity was observed between pH 7 and 11. In HA-inhibition assays performed with several carbohydrates and glycoproteins, LVL showed a distinct and unique specificity for GalNAc/GluNAc/NeuAc which had an acetyl group, while glycoproteins fetuin and bovine submaxillary mucin (BSM) had sialic acid. Moreover, this agglutinin appeared to recognise the terminal N- and O-acetyl groups in the oligosaccharide chain of glycoconjugates. The HA activity of L. vannamei lectin was also susceptible to inhibition by lipopolysaccharides from diverse Gram-negative bacteria, which might indicate a significant in vivo role of this humoral agglutinin in the host immune response against bacterial infections.
authors.affiliation: Institute of Oceanology, The Chinese Academy of Sciences, Qingdao 266071, Shandong, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Sun
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Baojie
authors.initials: B
authors.lastname: Wang
authors.forename: Zhenyu
authors.initials: Z
authors.lastname: Guo
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Keyong
authors.initials: K
authors.lastname: Jiang
authors.forename: Zuoyong
authors.initials: Z
authors.lastname: Luo
mesh_terms: D000818:Animals; D002645:Chickens; D020609:Edwardsiella tarda / Q000276:immunology; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000737:chemistry / Q000276:immunology; D006385:Hemagglutination Inhibition Tests; D006458:Hemolymph / Q000737:chemistry / Q000276:immunology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D051379:Mice; D008856:Microscopy, Fluorescence; D008970:Molecular Weight; D033561:Penaeidae / Q000737:chemistry* / Q000276:immunology; D013291:Streptococcus / Q000276:immunology; D013696:Temperature; D014733:Vibrio / Q000276:immunology
chemical_list: D037102:Lectins