title: Purification and characterization of a novel thermostable mycelial lectin from Aspergillus terricola.
abstract: Lectin has been isolated from mycelia of Aspergillus terricola by single step purification on porcine stomach mucin-Sepharose 4B affinity column. Lectin could be effectively purified with 75% recovery and 4.47-fold increase in specific activity. Lectin migrated as a single band on SDS-PAGE with an apparent molecular mass of 32.5 kDa. Sugar inhibition assay revealed that the lectin did not strongly interact with most carbohydrates and their derivatives tested while strong binding affinity to D-glucose, D-sucrose, N-acetyl-D-galactosamine, asialofetuin, porcine stomach mucin, and bovine submaxillary mucin was indicated. Neuraminidase and protease treatment to erythrocytes enhanced lectin titre. Lectin activity was stable within the pH range of 7.0-10.5. A. terricola lectin displayed remarkable thermostability and remained unaffected upon incubation at 70 degrees C for 2.5 h. Lectin did not require metal ions for its activity. Incubation with denaturants (urea, thiourea, and guanidine-HCl) substantially reduced lectin activity. Carbohydrate analysis revealed that it is a glycoprotein with 9.76% total sugars.
authors.affiliation: Carbohydrate and Protein Biotechnology Laboratory, Department of Biotechnology, Punjabi University, Patiala 147 002 Punjab, India. rssingh11@lycos.com
authors.forename: Ram Sarup
authors.initials: RS
authors.lastname: Singh
authors.forename: Ranjeeta
authors.initials: R
authors.lastname: Bhari
authors.forename: Hemant Preet
authors.initials: HP
authors.lastname: Kaur
authors.forename: Monika
authors.initials: M
authors.lastname: Vig
mesh_terms: D000818:Animals; D001230:Aspergillus / Q000737:chemistry* / Q000187:drug effects; D002417:Cattle; D002846:Chromatography, Affinity; D004492:Edetic Acid / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism; D006384:Hemagglutination / Q000187:drug effects; D006386:Hemagglutination Tests; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D037102:Lectins / Q000302:isolation & purification* / Q000378:metabolism; D025282:Mycelium / Q000737:chemistry* / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D055550:Protein Stability / Q000187:drug effects; D034421:Sus scrofa; D013696:Temperature
chemical_list: D037102:Lectins; D004492:Edetic Acid