| Autor: |
Robert M. Crowl, R Bhatt, P L Kilian, K L Kaffka, L Collins, W H Tsien, Richard Anthony Chizzonite, Grace Ju |
| Rok vydání: |
1987 |
| Předmět: |
|
| Zdroj: |
Journal of Biological Chemistry. 262:5723-5731 |
| ISSN: |
0021-9258 |
| DOI: |
10.1016/s0021-9258(18)45635-9 |
| Popis: |
To locate functional domains of the interleukin-2 (IL-2) protein, a cDNA clone encoding biologically active human IL-2 was mutagenized using synthetic oligonucleotides to incorporate defined amino acid substitutions and deletions in the mature protein. The IL-2 analogs were then produced in Escherichia coli and assayed for the ability to induce proliferation of IL-2-dependent cells and the ability to compete for binding to the IL-2 receptor. Our analysis of over 50 different mutations demonstrated that the integrity of at least three regions of the IL-2 molecule is required for full biological activity: the NH2 terminus (residues 1-20), the COOH terminus (residues 121-133), and 2 of the 3 cysteine residues (58 and 105). Deletion of the NH2-terminal 20 amino acids or the COOH-terminal 10 amino acids resulted in the loss of greater than 99% of bioactivity and binding. Amino acid substitutions at specific positions in these regions also resulted in proteins which retained less than 1% activity. The NH2 terminus and an adjacent internal region were recognized by neutralizing anti-IL-2 antibodies. In combination with the results from epitope competition analysis with neutralizing antibodies, these data are consistent with the IL-2 protein being folded such that the NH2 terminus, the COOH terminus, and the internal 30- to 60-region are juxtaposed to form the binding site recognized by the IL-2 receptor. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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