Identification of complexes between the tyrosine-O-sulphate-binding protein and tyrosine-sulphated proteins in bovine liver membrane lysates.
Rabbit antiserum against electrophoretically purified bovine liver tyrosine-O-sulphate (TyrS)-binding protein was prepared. Affinity-purified antibodies from the antiserum were found to be capable of immunoprecipitating the TyrS-binding protein from the sodium choleate extract of a bovine liver microsomal membrane fraction. Using purified specific antibodies as the probe, Western blot analysis for the presence of TyrS-binding protein/tyrosine-sulphated protein complexes in bovine liver membrane lysates was performed. It was found that the TyrS-binding protein co-precipitated with three tyrosine-sulphated proteins (fibronectin, fibrinogen and complement C4) immunoprecipitated by their respective antibodies. In contrast, for the two non-tyrosine-sulphated proteins (haptoglobin and transferrin) tested, co-precipitation of the TyrS-binding protein was not observed. On employing an affinity gel fractionation technique, it was shown that partially purified TyrS-binding protein exhibited binding affinity towards Sepharose gels covalently bonded to fibronectin or fibrinogen, but not towards Sepharose gels bonded to albumin or transferrin. These results indicate that the TyrS-binding protein formed complexes with tyrosine-sulphated proteins both in vivo and in vitro, and thus provide support for the putative role of the former being the receptor of the latter.
Liu
M C
MC
Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019.
Lu
R L
RL
Han
J R
JR
Tang
X B
XB
Suiko
M
M
Liu
C C
CC
D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000032:analysis / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002462:Cell Membrane / Q000737:chemistry; D003181:Complement C4 / Q000302:isolation & purification; D004591:Electrophoresis, Polyacrylamide Gel; D005340:Fibrinogen / Q000302:isolation & purification; D005353:Fibronectins / Q000302:isolation & purification; D007163:Immunosorbent Techniques; D036341:Intercellular Signaling Peptides and Proteins; D008099:Liver / Q000737:chemistry*; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism*; D008970:Molecular Weight; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D002352:Carrier Proteins; D003181:Complement C4; D005353:Fibronectins; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C057501:tyrosine-O-sulfate-binding protein, Bos taurus; C005662:tyrosine O-sulfate; D014443:Tyrosine; D005340:Fibrinogen