title: Insertion of a structural domain of interleukin (IL)-1 beta confers agonist activity to the IL-1 receptor antagonist. Implications for IL-1 bioactivity.
abstract: We showed previously that replacement of Lys-145 in the IL-1 receptor antagonist (IL-1ra) with Asp resulted in an analog (IL-1ra K145D) with partial agonist activity. To identify additional amino acids that affect IL-1 bioactivity, we created second site mutations in IL-1ra K145D. Substitutions of single amino acids surrounding position 145 were made; none of these substitutions increased the bioactivity of IL-1ra K145D. However, the insertion of the beta-bulge (QGEESN) of IL-1 beta at the corresponding region of IL-1ra K145D resulted in a 3-4-fold augmentation of bioactivity. An additional increase in agonist activity was observed when the beta-bulge was co-expressed with a second substitution (His-54 --> Pro) in IL-1ra K145D. We also show that the bioactivity of both IL-1ra K145D and the triple mutant IL-1ra K145D/H54P/QGEESN is dependent on interaction with the newly cloned IL-1 receptor accessory protein.
authors.affiliation: Department of Inflammation/Autoimmune Diseases, Hoffman-La Roche Inc., Nutley, New Jersey 07110, USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Greenfeder
authors.forename: T
authors.initials: T
authors.lastname: Varnell
authors.forename: G
authors.initials: G
authors.lastname: Powers
authors.forename: K
authors.initials: K
authors.lastname: Lombard-Gillooly
authors.forename: D
authors.initials: D
authors.lastname: Shuster
authors.forename: K W
authors.initials: KW
authors.lastname: McIntyre
authors.forename: D E
authors.initials: DE
authors.lastname: Ryan
authors.forename: W
authors.initials: W
authors.lastname: Levin
authors.forename: V
authors.initials: V
authors.lastname: Madison
authors.forename: G
authors.initials: G
authors.lastname: Ju
mesh_terms: D000595:Amino Acid Sequence; D001667:Binding, Competitive; D002455:Cell Division / Q000187:drug effects; D006801:Humans; D066298:In Vitro Techniques; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1 / Q000737:chemistry* / Q000494:pharmacology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017472:Receptors, Interleukin-1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000737:chemistry* / Q000494:pharmacology; D013329:Structure-Activity Relationship
chemical_list: C507763:IL1RN protein, human; D053590:Interleukin 1 Receptor Antagonist Protein; D007375:Interleukin-1; D017472:Receptors, Interleukin-1; D012795:Sialoglycoproteins