, 1955). The data were evaluated using analysis of variance followed by Student’s t-test. Results are expressed as mean ± SEM with the level of significance set at 5% (P < 0.05; n = 4). After the experiment, both right and left kidneys were removed and fixed in 10% formaldehyde for histological processing and examination. The experiments followed the methodology

recommended by International Ethical Standards in animal research and was approved by the Scientific and Ethical Committee of the Federal University of Ceará, Brazil. The crude extract of I. asarifolia leaves injured and kept in the dark for 72 h gave a hemagglutination specific activity of 650.9 ± 16.7 HU/mg click here protein whereas the crude extract from uninjuried leaves not kept in the dark (control) gave 416.9 ± 2.7 HU/mg protein. The increase in activity selleck chemicals in wounded/darkened leaves was due to the de novo synthesis of the native

leaf lectin because irrespective of wound treatment the lectin-enriched fraction (LEF) gave the same N-terminal amino acid sequence. Thus the starting material for LEF production was the crude extract of wounded/darkened leaves. This lectin-enriched fraction (LEF) from I. asarifolia leaves was obtained after protein extraction, ammonium sulfate precipitation, DEAE-cellulose and Phenyl-Sepharose 6-Fast Flow chromatographies, as detailed in 2.2. SDS–PAGE of LEF showed a main protein band with relative molecular weight of around 44.0 kDa ( Fig. 1, Lane 3). This band was electroblotted onto PVDF membrane and had its N-terminal amino acid sequence determined: AVNLPAGHLSPGGVGNYVVTVGLCTP. LEF had a specific hemagglutination activity of 1118 HU/mg protein. It was inhibited by the glycoprotein fetuin (3.0 × 10−3 mM), as well as by sialic acid (N-acetyl-d-neuramic acid, minimum inhibitory concentration of 3.0 mM) (Santos, 2001) which is a

component of fetuin. However it was not inhibited by the simple sugars d-arabinose, l-fructose, d-galactose, N-acetyl-d-galactosamine, d-glucose, N-acetyl-d-glucosamine, d-mannose, d-xilose, the disaccharides α-lactose, maltose, sacarose, and the trisaccharide d-raffinose, even at high concentration (100 mM), neither by the glycoproteins during BSA and mucin (Santos, 2001). Heat treatment at 70 and 80 °C for 60 min reduced LEF agglutination activity against trypsin-treated rabbit erythrocytes to 75% and at 90 °C it was completely abolished within 10 min (Fig. 2). Treatment of LEF with DTT (5, 10, 50 or 100 mM) had no influence on the hemagglutination activity. In vitro digestion of LEF with pepsin alone or pepsin followed by trypsin and chymotrypsin did not inactivate its hemagglutination activity. The biological assays done in this study were conducted with the LEF preparation showed in Fig. 1, lane 3. This preparation was free of secondary compounds as evaluated by NMR analysis (data not shown).