Characterization of murine IL-1 beta. Isolation, expression, and purification.
One cDNA clone encoding a truncated murine IL-1 beta (M IL-1 beta) sequence was isolated from a murine macrophage cDNA library. We reconstituted the coding sequence of the 152-residue mature protein and expressed it in Escherichia coli. rM IL-1 beta was purified to homogeneity and characterized by oligonucleotide and NH2-terminal sequence analysis. Purified rM IL-1 beta exhibited biologic activity equivalent to 7.8 x 10(7) units/mg in the murine thymocyte proliferation assay and 9.9 x 10(3) units/mg in the human gingival fibroblast PGE2 production assay, indicative of species specificity. The isoelectric point of rM IL-1 was found to be 8.85. The circular dichroism spectrum revealed that the secondary structure of M IL-1 is indistinguishable from that of the human protein. Receptor binding studies indicated the rM IL-1 bound to murine EL-4.1 thymoma cells in a specific and dose-dependent fashion with an affinity of 32 pM. Competition binding data suggested that murine and human IL-1 compete for a single class of receptor. Antisera were generated in rabbits against both murine and human IL-1. Results of ELISA binding and antisera neutralization assays indicated that there are common antigenic sites between the two IL-1 beta molecules. These domains are of functional importance because they are capable of mediating the neutralization of biologic activity.
Huang
J J
JJ
Medical Products Department, E.I. du Pont de Nemours & Company, Glenolden, PA 19036.
Newton
R C
RC
Rutledge
S J
SJ
Horuk
R
R
Matthew
J B
JB
Covington
M
M
Lin
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001667:Binding, Competitive; D002942:Circular Dichroism; D003001:Cloning, Molecular; D003429:Cross Reactions; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D051379:Mice / Q000276:immunology*; D008969:Molecular Sequence Data; D010957:Plasmids; D011971:Receptors, Immunologic / Q000032:analysis; D017472:Receptors, Interleukin-1
D007375:Interleukin-1; D011971:Receptors, Immunologic; D017472:Receptors, Interleukin-1