Purification and molecular characterization of a sialic acid specific lectin from the phytopathogenic fungus Macrophomina phaseolina.
A lectin was isolated and purified from the culture filtrate of the plant pathogenic fungus Macrophomina phaseolina by a combination of ammonium sulfate precipitation, affinity chromatography on fetuin-Sepharose 4B and ion-exchange chromatography on DEAE-A 50. The lectin designated MPL was homogeneous by PAGE and HPLC and a monomeric protein with a molecular weight of approximately 34 kDa as demonstrated by SDS-PAGE. It is a glycoprotein and agglutinated human erythrocytes regardless of the human blood type. Neuraminidase treatment of erythrocytes reduced the agglutination activity of the lectin. It is thermally stable and exhibits maximum activity between pH 6 and 7.2. Its carbohydrate binding specificity was investigated both by hapten inhibition of hemagglutination and by enzyme-conjugated lectin inhibition assay. Although, M. phaseolina lectin bound sialic acid, it exhibited binding affinity towards neuraminyl oligosaccharides of N-linked glycoproteins, alpha-Neu5Ac-(2-->3)-beta-Gal-(1-->4)-GlcNAc being maximum.
Bhowal
Jayati
J
Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India.
Guha
Arun Kumar
AK
Chatterjee
Bishnu Pada
BP
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001203:Ascomycota / Q000737:chemistry*; D001665:Binding Sites; D002118:Calcium / Q000494:pharmacology; D002240:Carbohydrate Sequence; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D006385:Hemagglutination Inhibition Tests; D006386:Hemagglutination Tests; D006801:Humans; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D003904:Mitosporic Fungi / Q000737:chemistry*; D008970:Molecular Weight; D013050:Spectrometry, Fluorescence
D000596:Amino Acids; D037102:Lectins; D002118:Calcium