Trophic hormone fusion protein, preparation method and application thereof

Abstract

Disclosed herein is a gonadotropin fusion protein or a thyroid stimulating hormone fusion protein, a method for preparing the same and use thereof. β-subunit of the gonadotropin or thyroid stimulating hormone is fused to an Fc fragment directly or indirectly through a linker, and α-subunit binds to the β-subunit via an affinity between the α-subunit and the β-subunit. The fusion protein has a prolonged half-life and less fluctuating activity.

What is claimed is: 
     
         1 . A fusion protein comprising a trophic hormone protein having an α-subunit, a β-subunit and an Fc fragment of an antibody, wherein the β-subunit of the trophic hormone protein is linked to the Fc fragment directly or indirectly via a linker, and the α-subunit of the trophic hormone protein binds to the β-subunit via intermolecular interactions between the α-subunit and the β-subunit, and wherein the α-subunit of the trophic hormone is not linked to an Fc fragment. 
     
     
         2 . (canceled) 
     
     
         3 . A homodimeric protein comprising two fusion proteins according to  claim 1 , wherein the Fc fragments in the two fusion proteins are associated with each other via chemical association. 
     
     
         4 . A mixture comprising
 a heterodimeric protein comprising a fusion protein that comprises a trophic hormone protein having an α-subunit and a β-subunit and an Fc fragment of an antibody, wherein the β-subunit of the trophic hormone protein is linked to the Fc fragment directly or indirectly via a linker, and the α-subunit of the trophic hormone protein binds to the β-subunit via intermolecular interactions between the α-subunit and the β-subunit, wherein the α-subunit of the trophic hormone is not linked to an Fc fragment, and wherein the Fc chain is associated with the Fc fragment in the fusion protein via chemical association; and   a homodimeric protein comprising two fusion proteins, wherein each fusion protein comprises a trophic hormone protein having an α-subunit and a β-subunit and an Fc fragment of an antibody, wherein the β-subunit of the trophic hormone protein is linked to the Fc fragment directly or indirectly via a linker, and the α-subunit of the trophic hormone protein binds to the β-subunit via intermolecular interactions between the α-subunit and the β-subunit, wherein the a-subunit of the trophic hormone is not linked to an Fc fragment, and wherein the Fc fragments in the two fusion proteins are associated with each other via chemical association.   
     
     
         5 . A pharmaceutical composition comprising the fusion protein according to  claim 1  and a pharmaceutically acceptable carrier or excipient. 
     
     
         6 - 11 . (canceled) 
     
     
         12 . A method for treating an abnormal trophic hormone disorder, comprising the step of administering to a mammal in need thereof an effective amount of a fusion protein comprising a trophic hormone protein having an α-subunit, a β-subunit and an Fc fragment of an antibody, wherein the β-subunit of the trophic hormone protein is linked to the Fc fragment directly or indirectly via a linker, and the α-subunit of the trophic hormone protein binds to the β-subunit via intermolecular interactions between the α-subunit and the β-subunit, wherein the α-subunit of the trophic hormone is not covalently linked to an Fc fragment. 
     
     
         13 . The homodimeric protein according to  claim 3 , wherein the trophic hormone is selected from the group consisting of luteotropic hormone, follicle stimulating hormone, chorionic gonadotropin and thyroid stimulating hormone. 
     
     
         14 . The homodimeric protein according to  claim 3 , wherein the trophic hormone is follicle stimulating hormone. 
     
     
         15 . The homodimeric protein according to  claim 3 , wherein the Fc fragment comprises a hinge region, a CH2 domain, and a CH3 domain of an immunoglobulin. 
     
     
         16 . The homodimeric protein according to  claim 3 , wherein the Fc fragment comprises an IgG1 Fc. 
     
     
         17 . The homodimeric protein according to  claim 14 , wherein the follicle stimulating hormone α-subunit comprises a sequence according to SEQ ID NO:1. 
     
     
         18 . The homodimeric protein according to  claim 14 , wherein the follicle stimulating hormone β-subunit linked to the FC fragment comprises a sequence according to SEQ ID NO:4. 
     
     
         19 . The homodimeric protein according to  claim 14 , wherein the follicle stimulating hormone α-subunit comprises a sequence according to SEQ ID NO:1 and the follicle stimulating hormone β-subunit linked to the FC fragment comprises a sequence according to SEQ ID NO:4. 
     
     
         20 . The homodimeric protein according to  claim 3 , wherein the homodimeric protein has the formula:
 αXXX@βXXX-L-Fc: αXXX@βXXX-L-Fc,   wherein “XXX” refers to luteotropic hormone, follicle stimulating hormone, chorionic gonadotropin or thyroid stimulating hormone protein,   “α” refers to the α-subunit of the trophic hormone protein,   “β” refers to the β-subunit of the trophic hormone protein,   “@” is the intermolecular interaction between the α-subunit and β-subunit of the trophic hormone protein,   “L” represents direct linking between the β-subunit and Fc fragment or indirect linking via a linker,   “Fc” refers to the Fc fragment of an immunoglobulin, and   “:” refers to the chemical association between the two αXXX@βXXX-L-Fc fusion proteins.   
     
     
         21 . The homodimeric protein according to  claim 3 , wherein the homodimeric protein has the formula:
 αFSH@βFSH-L-Fc:αFSH@βFSH-L-Fc,   wherein “FSH” refers to follicle stimulating hormone protein,   “α” refers to the α-subunit of the follicle stimulating hormone protein,   “β” refers to the β-subunit of the follicle stimulating hormone protein,   “@” is the intermolecular interaction between the α-subunit and β-subunit of the follicle stimulating hormone protein,   “L” represents direct linking between the β-subunit and Fc fragment or indirect linking via a linker,   “Fc” refers to the Fc fragment of an immunoglobulin, and   “:” refers to the chemical association between the two αFSH@βFSH-L-Fc fusion proteins.   
     
     
         22 . The homodimeric protein according to  claim 3 , wherein the homodimeric protein has the formula:
 Ta-αXXX@βXXX-L-Fc:Ta-αXXX@βXXX-L-Fc   wherein “XXX” refers to luteotropic hormone, follicle stimulating hormone, chorionic gonadotropin or thyroid stimulating hormone protein,   “α” refers to the α-subunit of the trophic hormone protein,   “β” refers to the β-subunit of the trophic hormone protein,   “@” is the intermolecular interaction between the α-subunit and β-subunit of the trophic hormone protein,   “L” represents direct linking between the β-subunit and Fc fragment or indirect linking via a linker,   “Fc” refers to the Fc fragment of an immunoglobulin,   “:” refers to the chemical association between the two αXXX@βXXX-L-Fc fusion proteins, and   “Ta” refers to a protein purification tag.   
     
     
         23 . The mixture according to  claim 4 , wherein the trophic hormone is selected from the group consisting of luteotropic hormone, follicle stimulating hormone, chorionic gonadotropin and thyroid stimulating hormone. 
     
     
         24 . The mixture according to  claim 4 , wherein the trophic hormone is follicle stimulating hormone.