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Effect of temperature on haemagglutinating activity and on the conformation of leucoagglutinin, a lectin from Phaseolus vulgaris (red kidney bean)
Author(s) -
Serafini-Cessi Franca,
Montanaro Lucio,
Sperti Simonetta
Publication year - 1980
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(80)81059-3
Subject(s) - humanities , phaseolus , philosophy , linguistics , biology , botany
One of the isolectins from P~~se~~~s vutgaris (red kidney bean) is called leucoagglutinin because of its high leucoagglutinating activity [ 11. This lectin consists of 4 identical subunits (L-subunit) which bind, with high affinity, glycidic receptors on lymphocyte surface membranes [2-31. It has been shown that leucoagglutinin interacts specifically with the glycomoiety of human TammHorsfall glycoprotein [4] and that the glycopeptide purified after pronase digestion of the ~ycoprotein is a powerful in~bito~ hapten of the precipitin reaction between leucoagglutinin and Tann-Horsfa~ glycoprotein [S]. Leucoagglutinin is also able to agglutinate neuraminidase-treated human erythrocytes and agglutination is inhibited by very low concentration (3.2 PM) of the glycopeptide isolated from human TammHorsfall glycoprotein (T-H-glycopeptide) [6]. Studies on the haemagglutinating activity of different lectins have shown that the rate of agglutination may be affected by temperature [7]. The erythrocyte a~utination by concanavalin A (con A) is reduced at low temperature [8]. This difference has been related to changes in the molecular conformation of the lectin [9,10]. This communication presents data on the agglutination of human desialylated erythrocytes by leucoagglutinin at different temperatures. The temperaturedependent changes of leucoagglutinin conjugated with fluorescent compounds were also investigated by the method of fluorescence polarization. The results obtained suggest that differences in the haemagglutinating activity of leucoagglutinin may be related to a change of the conformation of the molecule, bound to the glycidic receptors, induced by temperature.