TY - JOUR
T1 - Comparative cross-linking activities of lactose-specific plant and animal lectins and a natural lactose-binding immunoglobulin G fraction from human serum with asialofetuin
AU - Gupta, Dipti
AU - Kaltner, Herbert
AU - Dong, Xin
AU - Gabius, Hans Joachim
AU - Brewer, C. Fred
N1 - Funding Information:
This work was supported by Grant CA-16054 from the National Cancer Institute; Department of Health, Education and Welfare Core Grant P30 CA-13330; and Grant GA 349^7-1 from the Deutsche Forschungsgemeinschaft. The NMR facility at AECOM was supported by Instrumentation Grant I-SI0-RR02309 from the National Institutes of Health and DMB-8413723 from the National Science Foundation.
PY - 1996/12
Y1 - 1996/12
N2 - Plant and animal lectins bind and cross-link certain multiantennary oligosascharides, glycopeptides, and glycoproteins. This can lead to the formation of homogeneous crosslinked complexes, which may differ in their stoichiometry depending on the nature of the sugar receptor involved. As a precisely defined ligand, we have employed bovine asialofetuin (ASF), a glycoprotein that possesses three asparagine-linked triantennary complex carbohydrate chains with terminal LacNAc residues. In the present study, we have compared the carbohydrate cross-linking properties of two Lac-specific plant lectins, an animal lectin and a naturally occurring Lac-binding polyclonal immunoglobulin G subfraction from human serum with the ligand. Quantitative precipitation studies of the Lac-specific plant lectins. Viscum album agglutinin and Ricinus communis agglutinin, and the Lac-specific 16 kDa dimeric galectin from chicken liver demonstrate that these lectins form specific, stoichiometric cross-linked complexes with ASF. At low concentrations of ASF, 1:9 ASF/lectin (monomer) complexes formed with both plant lectins and the chicken lectin. With increasing concentrations of ASF, 1:3 ASF/lectin (monomer) complexes formed with the lectins irrespective of their source or size. The naturally occurring polyclonal antibodies, however, revealed a different cross-linking behavior. They show the formation of 1:3 ASF/antibody (per Fab moiety) cross-linked complexes at all concentrations of ASF. These studies demonstrate that Lac-specific plant and animal lectins as well as the Lac-binding immunoglobulin subfraction form specific stoichiometric cross-linked complexes with ASF. These results are discussed in terms of the structure-function properties of multivalent lectins and antibodies.
AB - Plant and animal lectins bind and cross-link certain multiantennary oligosascharides, glycopeptides, and glycoproteins. This can lead to the formation of homogeneous crosslinked complexes, which may differ in their stoichiometry depending on the nature of the sugar receptor involved. As a precisely defined ligand, we have employed bovine asialofetuin (ASF), a glycoprotein that possesses three asparagine-linked triantennary complex carbohydrate chains with terminal LacNAc residues. In the present study, we have compared the carbohydrate cross-linking properties of two Lac-specific plant lectins, an animal lectin and a naturally occurring Lac-binding polyclonal immunoglobulin G subfraction from human serum with the ligand. Quantitative precipitation studies of the Lac-specific plant lectins. Viscum album agglutinin and Ricinus communis agglutinin, and the Lac-specific 16 kDa dimeric galectin from chicken liver demonstrate that these lectins form specific, stoichiometric cross-linked complexes with ASF. At low concentrations of ASF, 1:9 ASF/lectin (monomer) complexes formed with both plant lectins and the chicken lectin. With increasing concentrations of ASF, 1:3 ASF/lectin (monomer) complexes formed with the lectins irrespective of their source or size. The naturally occurring polyclonal antibodies, however, revealed a different cross-linking behavior. They show the formation of 1:3 ASF/antibody (per Fab moiety) cross-linked complexes at all concentrations of ASF. These studies demonstrate that Lac-specific plant and animal lectins as well as the Lac-binding immunoglobulin subfraction form specific stoichiometric cross-linked complexes with ASF. These results are discussed in terms of the structure-function properties of multivalent lectins and antibodies.
KW - Asialofetuin
KW - Immunoglobulin subfraction
KW - Lac-specific lectins
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U2 - 10.1093/glycob/6.8.843
DO - 10.1093/glycob/6.8.843
M3 - Article
C2 - 9023547
AN - SCOPUS:0030445222
SN - 0959-6658
VL - 6
SP - 843
EP - 849
JO - Glycobiology
JF - Glycobiology
IS - 8
ER -