New deletion mutants of Interleukin-6 receptor protein useful for production of cell proliferation inhibitors for treatment of tumors, especially multiple myeloma

摘要

Interleukin-6 (IL-6) receptor protein shortened by an amino acid deletion in the beta chain is new. The shortened beta chain, DNA coding for the shortened protein or beta chain and RNA derived from the DNA are also new. Further, inhibitors which block the binding of Hck-tyrosine kinase to the beta chain are new. The IL-6 receptor protein has a deletion in the beta chain (gp130) region of at least some or all of amino acids 771-811 so that the specific binding of Hck-tyrosine kinase to gp130 is prevented. Independent claims are also included for the following: (1) beta chain (gp130) of the receptor protein with the specified amino acid deletion; (2) DNA coding for the IL-6 receptor protein or beta chain (gp130); (3) RNA derived from the DNA; and (4) an inhibitor which specifically blocks the binding of Hck-tyrosine kinase to gp130 in the region of amino acids 771-811.