Novel lectin-like proteins on the surface of human monocytic leukemia cell line THP-1 cells that recognize oxidized cells.
Presence of lectin-like receptors on the membranes of human monocytic leukemia cell line THP-1 cells for clustered sialylated poly-N-acetyllactosaminyl sugar chains on the membranes of oxidized erythrocytes and T-lympoid cells was investigated. Membranes of THP-1 cells differentiated into macrophages were solubilized, and the membrane proteins obtained by affinity chromatographies using lactoferrin-Sepharose and band 3-Sepharose were purified by successive DE column chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Proteins of 50, 60, and 80 kDa with specificity to bind to sialylated poly-N-acetyllactosaminyl sugar chains were detected in the chromatographic fractions. A 50-kDa protein was isolated in a pure form. N-Terminal amino acid sequence of the protein was Lys-Gln-Lys-Val-Ala-Gly-Lys-Gln-Pro-Val-, which has not been found in the N-terminal regions of the hitherto known proteins. The antibody, raised against the chemially synthesized peptide composed of the N-terminal amino acid sequence, bound to 50-, 60-, and 80-kDa proteins as analyzed by immunoblotting and immunoprecipitation, indicating that these proteins had the same N-terminal amino acid sequence. The results demonstrate that THP-1 cells have novel 50-, 60-, and 80-kDa lectin-like proteins with the same N-terminal amino acid sequence on the cell surface which would bind to clustered sialylated poly-N-acetyllactosaminyl sugar chains generated on oxidized erythrocytes and T-lymphoid cells.
Eda
S
S
School of Pharmacy, Tokyo University of Pharmacy and Life Science, Hachioji, Japan.
Beppu
M
M
Yokoyama
N
N
Kikugawa
K
K
D000595:Amino Acid Sequence; D015153:Blotting, Western; D002458:Cell Fractionation; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002846:Chromatography, Affinity; D002847:Chromatography, Agarose; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015151:Immunoblotting; D007074:Immunoglobulin G / Q000378:metabolism; D007781:Lactoferrin / Q000378:metabolism; D037102:Lectins / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism; D008969:Molecular Sequence Data; D009000:Monocytes / Q000166:cytology* / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D011233:Precipitin Tests; D011485:Protein Binding; D012685:Sepharose / Q000378:metabolism
D007074:Immunoglobulin G; D037102:Lectins; D012685:Sepharose; D007781:Lactoferrin; D010100:Oxygen