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This study aimed to purify and characterize a novel mannose-binding lectin from the seeds of Centrolobium microchaete . Centrolobium microchaete lectin (CML) was purified by affinity chromatography in mannose-Sepharose-4B column. CML agglutinated rabbit erythrocytes and was inhibited by D-mannose, α-methyl-D-mannoside, D-glucose, N-Acetyl-D-glucosamine and sucrose. The lectin was stable at pH 7.0 and 8.0 and temperatures up to 60 °C. The monomeric form of CML showed approximately 28 kDa, and its native form is probably a homodimer, as determined by gel filtration chromatography. The primary structure of CML was determined by tandem mass spectrometry that showed CML as a protein with two distinct forms (isolectins CML-1 and CML-2) with 246 and 247 residues, respectively. CML-2 possesses one residue of Asn more than CML-1 in C-terminal. The primary structure of CML agrees with the molecular weights found by electrospray ionization mass spectrometry: 27,224 and 27,338 Da for CML-1 and CML-2, respectively. CML is a metal-dependent glycoprotein. Moreover, the glycan composition of CML and its structure were predicted. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the antihyperglycemic, antilipidemic, and antioxidant effects of a lectin isolated from Bryothamnion seaforthii (BSL), on rats with streptozotocin (STZ)-induced diabetes. The disease model was induced by low-dose injections of STZ. Diabetic rats were treated with NaCl 150 mM, metformin, and BSL at different concentrations. Blood collection was carried out at 0, 30, 60, 90, and 120 days after hyperglycemia confirmation via the assessment of seric glucose, total cholesterol, and triglycerides, assessment of the enzymatic levels of glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), and the determination of insulin resistance by a homeostasis model of assessment-insulin resistance (HOMA-IR) as well as a homeostasis model of assessment of β-cells resistance (HOMA-β). The BSL-treated animals at all three concentrations showed a significant reduction in levels of glucose, cholesterol, total cholesterol, and triglycerides. Moreover, BSL increased the enzymatic activity of GPx and SOD. Index assessments of HOMA-IR and HOMA-β confirmed that BSL treatment significantly decreased insulin resistance and β-cell hypersecretion, respectively. In conclusion, BSL treatment might exert hypoglycemic and hypolipidemic effects, diminish insulin resistance, and ameliorate pancreatic β-cell function along with enzymatic activities toward oxidative stress caused by diabetes mellitus type 2 (T2DM). [ABSTRACT FROM AUTHOR]

A new lectin from the marine sponge Chondrilla caribensis (CCL) was isolated by affinity chromatography in Sepharose 6B media. CCL is a homotetrameric protein formed by subunits of 15,445 ±2 Da. The lectin showed affinity for disaccharides containing galactose and mucin. Mass spectrometric analysis revealed about 50% of amino acid sequence of CCL, which showed similarity with a lectin isolated from Aplysina lactuca . Secondary structure consisted of 10% α-helix, 74% β-sheet/β-turn and 16% coil, and this profile was unaltered in a broad range of pH and temperatures. CCL agglutinated Staphylococcus aureus , S epidermidis and Escherichia coli , and it was able to reduce biofilm biomass, but showed no inhibition of planktonic growth of these bacteria. CCL activity was inhibited by α-lactose, indicating that Carbohydrate Recognition Domain (CRD) of the lectin was involved in antibiofilm activity. [ABSTRACT FROM AUTHOR]