Interaction of the pre-domain of interleukin-1 with the mature domain.
The two interleukin 1 precursors (preIL-1alpha and beta) with a molecular mass of 33 kDa are proteolytically processed to the mature carboxyl-terminal 17-kDa proteins. In this study we newly developed a monoclonal antibody against the precursor domain of IL-1beta (ED7), of which the binding to preIL-1beta was hindered by a polyclonal antibody against the mature domain of IL-1beta. Immunoprecipitation of limited proteolysed preIL-1beta by ED7 suggested that the epitope for ED7 may not be localized at the junction between preIL-1beta and mature IL-1beta. We therefore examined the possibility that the pre-domain of IL-1beta might interact with the mature domain by using chemical cross-linking. V8 protease yielded a mature 17.5-kDa protein from untreated preIL-1beta, but not chemically cross-linked preIL-1beta. However, cleavage of the cross-link with 2-mercaptoethanol liberated a mature 17.5-kDa protein from preIL-1beta, suggesting that the pre-domains of IL-1beta might interact with the mature domain. Similar phenomena were observed with preIL-1alpha. Such an intermolecular interaction may inhibit or modulate the biological activity of mature IL-1s.
Kobayashi
Y
Y
Department of Biomolecular Science, Faculty of Science, Toho University, Funabashi, Chiba. yoshiro@biomol.sci.toho-u.ac.jp
Nagatake
H
H
Shimozato
O
O
Watanabe
N
N
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D003432:Cross-Linking Reagents / Q000378:metabolism; D000939:Epitopes / Q000032:analysis; D006801:Humans; D006868:Hydrolysis; D007375:Interleukin-1 / Q000737:chemistry* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011233:Precipitin Tests; D011485:Protein Binding; D011498:Protein Precursors / Q000737:chemistry* / Q000276:immunology; D017434:Protein Structure, Tertiary
D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D000939:Epitopes; D007375:Interleukin-1; D011498:Protein Precursors