- D. B. Carter, K. A. Curry, +14 authors H. M. Einspahr
- Function and Genetics, 3, 121 129
Three distinct N-terminal variants of rhIL-1β can be generated by expression of the IL-1β gene in E. coli; the naturally occurring Ala1 species, Met0-Ala1 and des-Ala1 proteins. Since most studies with rhIL-1β have used a mixture of two or more variants, we have evaluated their individual bioactivities. The variants were resolved by cation exchange HPLC. Bioactivity measurement on murine thymocytes gave a potency order of Ala1 > des-Ala1 > Met0-IL-1β. Analysis using human T-cells co-stimulated with PMA showed a potency order of Ala1 > des-Ala1 > Met0-IL-1β. Thus changes in the N-terminal amino acid of IL-1β changes the activity of the protein. Since murine and human T-cells respond similarly, the interactions between the N-terminus of rhIL-1β and their receptors probably occur through comparable mechanisms.