Studies on the tryptophan residues of soybean agglutinin. Involvement in saccharide binding.
Modification of tryptophan side chains of soybean agglutinin (SBA) with N-bromosuccinimide results in a loss of the hemagglutinating and carbohydrate binding activities of the protein. One residue/subunit is probably essential for the binding activity. Modification leads to a large decrease in the fluorescence of the protein accompanied by a blue shift. Iodide ion quenching of the protein fluorescence shows that saccharide binding results in a decreased accessibility of some of the tryptophan side chains. These results strongly point towards the involvement of tryptophan residues in the active site of SBA.
UGC Centre of Advanced Study, Indian Institute of Science, Bangalore.
M J
MJ
Swamy
A
A
Surolia
D001974:Bromosuccinimide; D050260:Carbohydrate Metabolism; D007455:Iodine; D037102:Lectins / Q000032:analysis* / Q000378:metabolism; D037121:Plant Lectins; D030262:Soybean Proteins; D013050:Spectrometry, Fluorescence; D014364:Tryptophan / Q000032:analysis* / Q000378:metabolism; D010835:Phytohemagglutinins
D001974:Bromosuccinimide; D007455:Iodine; D037102:Lectins; D037121:Plant Lectins; D030262:Soybean Proteins; D014364:Tryptophan; C028824:soybean lectin; D010835:Phytohemagglutinins