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.
Swamy
M J
MJ
UGC Centre of Advanced Study, Indian Institute of Science, Bangalore.
Surolia
A
A
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