Mitogenic leukoagglutinin from Phaseolus vulgaris binds to a pentasaccharide unit in N-acetyllactosamine-type glycoprotein glycans.

Abstract

The carbohydrate binding specificity of leukoagglutinin (La; Phaseolus vulgaris isolectin L4) was studied by using quantitative precipitation and precipitation-inhibition. A series of purified glycopeptides and synthetic oligosaccharides were used as inhibitors. The minimal structural unit required for La binding was the disaccharide GlcNAc(1-+2)Man. Additions for this basic unit of different sugar residues gave a positive or negative contribution to binding. The most complementary structure was the pentasaccharide Gal(1-.>4)GlcNAc(1-*2)Man 6 Gal(1-*4)GlcNAc. This pentasaccharide unit occurs in tetraantennary N-acetyllactosamine-type glycoprotein glycans. Glycoproteins containing such structures were accordingly precipitated by La. Selected glycopeptides and oligosaccharides were also tested as inhibitors of La-induced DNA synthesis in human lymphocytes. The pattern of inhibition was essentially the same as that obtained by precipitation-inhibition, indicating that binding to lymphocytes via the carbohydrate binding site of the lectin is an essential step in the activation process.

Purification and cDNA cloning of a lectin and a lectin-like protein from Apios americana Medikus tubers

“…Among legume lectins, PHA (PHA-L) from P. vulgaris, 29) GSL-IV from G. simplicifolia, 30) MAL from Maackia amurensis, 31) and UEA-II from U. europaeus 32) are known as oligosaccharide-specific lectins. Since PHA (specific for oligosaccharides containing galactose/GalNAc at a terminal) and UEA-II (GlcNAcGlcNAc) are commercially available, their hemagglutinating activities and inhibition were investigated by the use of rabbit erythrocytes and glycoproteins.…”

The Preferred Conformation of Oligosaccharides Derived from the Complex‐Type Carbohydrate Portions of Glycoproteins

“…The mammalian hepatic lectin which binds to the /I-D-galactosyl groups in structure A is a well known example [3]. Leukoagglutinin, a mitogenic lectin isolated from Phaseolus vulgaris, binds to a pentasaccharide unit which is constructed of chains 111 and IV in structure A [4]. We have earlier reported the synthesis of several oligosaccharides derived from structure A [S].…”

Highly Sensitive Methods Using Liquid Chromatography and Capillary Electrophoresis for Quantitative Analysis of Glycoprotein Glycans

“…DSA is specific to polylactosamine and tetraantennary oligosaccharides [29]. PWM is specific to Nacetyllactosamine [30], and PHA-L4 recognizes some triand tetraantennary oligosaccharides [31,32]. Electropherograms obtained in the presence of these lectins were approximately identical to the reference electropherogram shown at the bottom of Fig.…”