Isolation and general characteristics of lectin from the mussel Mytilus trossulus

Abstract

Lectin (MTL) of molecular weight 16,492 Da and pI 6.09 ± 0.01 that was most active in the pH range 9.0-10.0, was thermally labile, and did not require Ca 2+ for activation was isolated from the mussel Mytilus trossulus. The MTL was a Gal/GalNAc-specific lectin that exhibited an affinity for glycoproteins containing mucin-type chains. The cross reactivity between MTL and a lectin isolated from the mussel Crenomytilus grayanus was determined. It was shown that MTL at high concentration stimulated expression of TNF-D and IFN-J; at low concentration, exhibited immunomodulating activity by reducing hyperexpression of cytokine IL-10.Lectins are proteins or glycoproteins that bind specifically and reversibly mono-and oligosaccharides and glycoconjugates without transforming them chemically. Lectins have now been observed in all biological taxa [1]. Marine invertebrates represent a comparatively new source of lectins. With respect to evolution, lectins of invertebrates are precursors of mammalian antibodies and form a primitive immune system. Furthermore, they exhibit antibacterial, cytotoxic, antitumor, mitogenic, and anti-HIV activities [2][3][4][5][6]. The goal of the present work was to isolate and study the physicochemical characteristics of lectin from the mussel Mytilus trossulus.This mussel is cultivated and widely distributed in the Far East. Proteins exhibiting hemagglutinating activity were observed previously in the mantle extract of this mollusk [7]. Therefore, the mantle of mussels collected in Troits Bay (Poset Gulf, Sea of Japan) was used to isolate lectin. Lectin was separated by affinity chromatography on porcine stomach mucin (PSM) and Sepharose. Lectin bound to the sorbent was eluted by Gal solution and purified by gel-permeation chromatography over Sephacryl S-200. A homogeneous protein of molecular weight ~18 kDa that was called MTL was obtained according to SDS-electrophoresis (in the presence and absence of E-mercaptoethanol).The lectin showed the greatest hemagglutinating activity in the reaction with trypsinized human group A erythrocytes. The yield of lectin calculated per gram of crude mollusk mantle was 23 Pg/g. This result was comparable with that for lectins from other marine bivalve mollusks [8][9][10]. The exact lectin molecular weight determined by mass spectrometry was 16,492 Da. The isoelectric point from capillary electrophoresis results was 6.09 ± 0.01. This was consistent with the aminoacid composition of the lectin. MTL contained a large number of non-polar amino acids (39.66%) and negatively charged amino acids (26.90%). The content of positively charged amino acids was insignificant (10.44%).The thermal stability and pH and metal dependences of the lectin were studied using hemagglutination (HA). The lectin exhibited the greatest hemagglutination titre in the pH range 9.0-10.0. The lectin activity fell by 25% at pH 6.0 and by 50% at pH 4.0. Furthermore, MTL was completely inactivated after incubation at 60°C for 30 min. Both metal-independent [8,9] and metal-dependent lectins wer...

Activity Dependence of a Novel Lectin Family on Structure and Carbohydrate-Binding Properties

“…This view was fully confirmed by a transcriptome analysis performed in M. galloprovincialis, which indicated the presence in the same species of two other sequences named MytiLec-2 and MytiLec-3 similar to MytiLec-1 [20]. A new GalNAc/Gal-specific lectin (MTL) from sea mussel Mytilus trossulus was later isolated and characterized [21]. The genera Mytilus and Crenomytilus are close to each other according genome analysis [22].…”

“…Cytokines-stimulation activity of CGL (unpublished data) and MTL[21] on spontaneous production of (a) TNF-α and (b) IFN-γ by HPBC. Cells were incubated for 24 h with or without lectin.…”

Antimicrobial and Immunomodulatory Properties and Applications of Marine-Derived Proteins and Peptides

“…Microbes recognition occurs via phagocytosis or the lectin pathway in the complement system. The lectin from the mussel Mytilus trossulus stimulates the induction of proinflammatory cytokines such as TNF-α and IFN-γ but reduces the anaphylaxis of the anti-inflammatory cytokine IL-10 in human peripheral blood cells (Figure 2) [33]. Lectins, derived from the hemolymph of crustaceans, are considered as active precursors of antibodies because they play an important role in antimicrobial activity as well as immune recognition [34].…”

Porifera Lectins: Diversity, Physiological Roles and Biotechnological Potential

“…Human galectin 3 also displayed chemotactic activity on neutrophils and macrophages as described for AcL and CvL [ 53 , 142 , 145 ]. Pro-inflammatory properties were also observed for lectins from other organisms, such as the algae Ticocarpus crinitus and the mussel Mytilus trossulus lectins, which showed to stimulate the cytokine production and the lymphocyte proliferation [ 14 , 15 ].…”

“…However, a stimulating activity on spontaneous and induced production of IFNγ was only observed at a concentration of 80 μg/mL. The growth of lymphocytes was also stimulated by the mussel M. trossulus lectin [ 15 ].…”