Purification and characterization of a 26‐kDa competitive inhibitor of interleukin 1

Abstract

The urine of patients with fever above 39 degrees C contains an inhibitor of interleukin 1. Herein we describe the purification of the interleukin 1 inhibitor by ion-exchange chromatography, hydrophobic chromatography, gel filtration and negative immunosorption. The purified protein has a molecular weight of 26,000; its size is reduced to 24,000 upon treatment with endoglycosidase F. The IL 1 inhibitor is a competitive inhibitor and acts by binding to the IL 1 receptor. The inhibitor recognizes the murine and human IL 1 receptor with similar affinity. The purified IL 1 inhibitor has a specific activity of 3 x 10(7) to 4.5 x 10(7) units/mg as tested on the human astrocytoma (U-373) cell proliferation bioassay and murine EL4.6.1 cell IL 1 receptor-binding assay.

The pivotal role of interleukin-1 in the clinical manifestations of rheumatoid arthritis

“…A protein with a mol. wt of~17 kDa was partially purified from the urine of afebrile patients; this was found specifically to inhibit the biological activities of IL-1 without affecting those of TNFα [40,41]. Around the same time, Arend and co-workers [42] made the independent observation of an inhibitor of chondrocyte and thymocyte responsiveness to IL-1 in cultured human monocytes.…”

“…Based on the inhibiting effect of natural IL-1Ra on the binding of IL-1 to lymphocytes, IL-1Ra was fully purified and cloned at Synergen in 1990 [44,45]. DNA encoding the IL-1Ra protein was obtained from a human monocyte library and the endogenous IL-1Ra partially purified from the urine of patients was found to be similar to recombinant IL-1Ra [41,46].…”

Factors Affecting IL-1-Mediated Collagen Metabolism By Fibroblasts and the Pathogenesis of Periodontal Disease: A Review of the Literature

“…A human IL-1 inhibitor has been partially purified from the urine of febrile patients (Liao et al, 1985;Seckinger et al, 1987). The urine inhibitor specifically blocked the binding of IL-1 to its receptor and inhibited IL-i-dependent T-cell activity and IL-1-induced collagenase production by fibroblasts (Seckinger et al, 1987;Mazzei et al, 1990). There is no evidence of IL-1 inhibitors in urine from patients with periodontal diseases.…”

Interleukin 1 receptor antagonist. A new member of the interleukin 1 family.

“…What is the evidence that the IL-I inhibitory activity in human urine represents the same protein? This molecule was purified from the urine offebrile patients, although no amino acid sequence analysis was reported (21). The urine-derived molecule demonstrated similar biological properties of an IL-I receptor antagonist as did the native or recombinant monocyte molecule.…”