Comparison of three different forms of HLA-DR4Dw4 proteins.
The biochemical behavior and peptide binding properties of a soluble form of the human class II DR4Dw4 molecule (PI-DR4Dw4) were compared to DR4Dw4 molecules containing the transmembrane and cytoplasmic domains that were purified both from B and transfected chinese hamster ovary cells. Recombinant and B cell-derived DR4Dw4 molecules bound monoclonal anti-DR4Dw4 antibodies with different affinities and varied in their stability in the presence of sodium dodecyl sulfate. The three forms of DR4Dw4 bound peptides with a similar apparent affinity constant, but soluble class II molecules bound up to ten times more peptide than DR4Dw4 containing a transmembrane region. Peptide binding kinetics for soluble DR4Dw4 molecules were 10-20 times faster than for the other two forms of DR4Dw4 molecules. Finally, soluble PI-DR4Dw4/peptide complexes were shown to stimulate T cell proliferation.
Buelow
R
R
Immunologic Pharmaceutical Corporation, Palo Alto, CA 94304.
Paborsky
L R
LR
van Schooten
W C
WC
Kummerehl
T J
TJ
Schreifels
R
R
Marshall
K
K
Mayer
J
J
Rothbard
J B
JB
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D001483:Base Sequence; D016466:CHO Cells; D002241:Carbohydrates / Q000032:analysis; D006224:Cricetinae; D004797:Enzyme-Linked Immunosorbent Assay; D006684:HLA-DR Antigens / Q000032:analysis* / Q000276:immunology / Q000378:metabolism; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism; D011487:Protein Conformation; D013601:T-Lymphocytes / Q000276:immunology; D014162:Transfection
D000911:Antibodies, Monoclonal; D002241:Carbohydrates; D006684:HLA-DR Antigens; D010455:Peptides