Coagulant Activity of Water-Soluble Moringa oleifera Lectin Is Linked to Lowering of Electrical Resistance and Inhibited by Monosaccharides and Magnesium Ions

• Published in: Applied biochemistry and biotechnology Vol. 180; no. 7; pp. 1361 - 1371
• Main Authors: de Moura, Kézia Santana, da Silva, Hugo Rafael Chaves, Dornelles, Leonardo Prezzi, Coelho, Luana Cassandra Breitenbach Barroso, Napoleão, Thiago Henrique, de Oliveira, Maria Danielly Lima, Paiva, Patrícia Maria Guedes
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-12-2016; Springer Nature B.V
• Subjects: Animals; Biochemistry; Biotechnology; Carbohydrates; Chemistry; Chemistry and Materials Science; Chromatography, Gel; Coagulants - pharmacology; Electric Impedance; Electric resistance; Electrolytes; Flocculation - drug effects; Hemagglutination - drug effects; Ions; Lectins; Lectins - pharmacology; Magnesium; Magnesium - pharmacology; Monosaccharides - pharmacology; Moringa oleifera; Moringa oleifera - chemistry; Rabbits; Seeds; Solubility; Water - chemistry; Water treatment; Lectin; Coagulant activity; Magnesium; Kaolin; Electric resistance; Monosaccharides
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-016-2172-y

Moringa oleifera
seeds contain a water-soluble lectin [water-soluble
M. oleifera
lectin (WSMoL)] that has shown coagulant activity. Magnesium ions are able to interfere with the ability of this lectin to bind carbohydrates. In this study, we performed structural characterization of WSMoL and analyzed its effect on the electrical resistance of a kaolin clay suspension in both presence and absence of monosaccharides (
N
-acetylglucosamine, glucose, or fructose) and magnesium ions. The coagulant activity of WSMoL was monitored by measuring optical density and electrical resistance over a period of 60 min. Native WSMoL had a molecular mass of 60 kDa and exhibited anionic nature (pI 5.5). In sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), it appeared as three polypeptide bands of 30, 20, and 10 kDa. WSMoL reduced the optical density and electrical resistance of the kaolin suspension, which suggests that suspended particles are destabilized and that this is followed by formation of complexes. The coagulant activity of lectin decreased in the presence of Mg
2+
ions and carbohydrates at concentrations that also inhibited hemagglutinating activity. This was most likely due to conformational changes in lectin structure. Our findings suggest that the coagulant activity of WSMoL is enhanced by lowering of electrical resistance of the medium and is impaired by lectin–carbohydrate and lectin–Mg
2+
interactions.