Compositions and methods for purifying and crystallizing molecules of interest

Abstract

A composition-of-matter is provided. The composition comprising at least one antibody binding moiety capable of binding an antibody-labeled target molecule, cell or virus of interest, said at least one antibody binding moiety being attached to at least one coordinating moiety selected capable of directing the composition-of-matter to form a non-covalent complex when co-incubated with a coordinator ion or molecule.

1 . A composition-of-matter comprising at least one antibody binding moiety capable of binding an antibody-labeled target molecule, cell or virus of interest, said at least one antibody binding moiety being attached to at least two coordinating moieties selected capable of directing the composition-of-matter to form a non-covalent complex when co-incubated with a coordinator ion or molecule. 
     
     
         2 . The composition-of-matter of  claim 1 , wherein said antibody-labeled molecule, target cell or virus comprises at least two distinct antibody labels. 
     
     
         3 . The composition-of-matter of  claim 1 , wherein said antibody binding moiety is selected from the group consisting of a protein A, a protein G, a protein L and a fragment thereof. 
     
     
         4 . The composition-of-matter of  claim 6 , wherein said antibody binding moiety comprise an antibody or an antibody fragment. 
     
     
         5 . The composition of  claim 1 , wherein said complex is a polymeric complex. 
     
     
         6 . The composition of  claim 1 , further comprising said coordinator ion or molecule. 
     
     
         7 . The composition of  claim 1 , wherein said at least one antibody binding moiety is attached to said at least one coordinating moiety via a linker. 
     
     
         8 . The composition of  claim 1 , wherein said coordinating moieties are selected from the group consisting of a biotin, a nucleic acid sequence, an epitope tag, an electron poor molecule and an electron-rich molecule. 
     
     
         9 . The composition of  claim 1 , wherein said coordinating moieties comprise a chelator. 
     
     
         10 . The composition of  claim 1 , wherein said coordinator ion or molecule is selected from the group consisting of an avidin, a nucleic acid sequence, an electron poor molecule and an electron-rich molecule. 
     
     
         11 . The composition of  claim 1 , wherein said coordinator ion or molecule is a metal ion. 
     
     
         12 . The composition of  claim 1 , wherein said at least one antibody binding moiety is non-immobilized. 
     
     
         13 . The composition of  claim 1 , wherein said at least one coordinating moiety comprise desthiobiotin. 
     
     
         14 . The composition of  claim 1 , wherein said coordinator comprise a monomeric or oligomeric avidin analog. 
     
     
         15 . A method of purifying a target molecule, cell or a virus of interest, the method comprising:
 (a) labeling the target molecule, cell or the virus with at least one antibody, so as to obtain antibody labeled target molecule, cell or the virus;   (b) contacting the antibody labeled target molecule, cell or the virus with the composition of  claim 1  so as to form a precipitate including said complex bound to the target molecule cell or the virus; and   (c) collecting said precipitate, thereby purifying the molecule, target molecule or cell of interest.   
     
     
         16 . The method of  claim 15 , wherein said step a and step b are effected sequentially. 
     
     
         17 . The method of  claim 15 , wherein said step a and step b are effected concomitantly. 
     
     
         18 . The method of  claim 15 , wherein said steps (a) and (b) are effected in a tube and the method further comprising spinning said tube around its axis so as to promote formation of said precipitate following step (b). 
     
     
         19 . A method of depleting a target molecule, cell or virus of interest from a sample, the method comprising:
 (a) labeling the target molecule, cell or the virus with an antibody, so as to obtain antibody labeled target molecule cell or the virus;   (b) contacting the antibody labeled target molecule, cell or the virus with the composition of  claim 1  so as to form a precipitate including said complex bound to the target molecule cell or the virus; and   (b) removing said precipitate to thereby deplete the target molecule or cell of interest from the sample.   
     
     
         20 . The method of  claim 19 , wherein said steps (a) and (b) are effected in a tube and the method further comprising spinning said tube around its axis so as to promote formation of said precipitate following step (b). 
     
     
         21 . A kit for isolating a target molecule cell or a virus of interest from a biological sample, the kit comprising a packaging material which comprises the composition-of-matter of  claim 1 . 
     
     
         22 . The kit of  claim 21 , wherein said composition-of-matter of  claim 1  is non-immobilized. 
     
     
         23 . A method of detecting predisposition to, or presence of a disease associated with a molecule, a cell or virus of interest in a subject, the method comprising contacting an immunolabeled biological sample obtained from the subject with the composition of  claim 1 , wherein formation of said complex including the molecule, cell or virus of interest is indicative of predisposition to, or presence of the disease associated with the molecule, cell or virus of interest in the subject. 
     
     
         24 . A composition-of-matter comprising at least one ligand capable of binding a target molecule or cell of interest, said at least one ligand being a composite ligand which comprises a scaffold moiety attached to at least one target recognition moiety capable of directly or indirectly binding the target molecule, cell or virus, said at least one ligand being attached to at least two coordinating moieties selected capable of directing the composition-of-matter to form a non-covalent complex when co-incubated with a coordinator ion or molecule. 
     
     
         25 . The composition-of-matter of  claim 24 , wherein said scaffold moiety comprise albumin. 
     
     
         26 . The composition-of-matter of  claim 24 , wherein said target recognition moiety is selected from the group consisting of glutathione, a nucleic acid sequence, an amino acid sequence, a hormone, a histidine, a protease substrate, a protease inhibitor, a lectin, a Lad, a Cibacron blue, a zinc finger protein and a chelator. 
     
     
         27 . The composition-of-matter of  claim 24 , wherein said at least one ligand is non-immobilized. 
     
     
         28 . A method of purifying at least one target molecule, cell or a virus of interest, the method comprising:
 (a) contacting the target molecule, cell or the virus with the composition of  claim 24  so as to form a precipitate including said complex bound to the target molecule cell or the virus; and   (b) collecting said precipitate, thereby purifying the at least one molecule, target molecule or cell of interest.   
     
     
         29 . The method of  claim 28 , wherein said step a and step b are effected sequentially. 
     
     
         30 . The method of  claim 28 , wherein said step a and step b are effected concomitantly. 
     
     
         31 . A method of depleting at least one target molecule, cell or virus of interest from a sample, the method comprising:
 (a) contacting the target molecule, cell or the virus with the composition of  claim 24  so as to form a precipitate including said complex bound to the target molecule cell or the virus; and   (b) removing said precipitate to thereby deplete the at least one target molecule or cell of interest from the sample.   
     
     
         32 . The method of  claim 31 , wherein said at least one target molecule comprise immunoglobulins and bovine serum albumin. 
     
     
         33 . A composition-of-matter comprising at least one ligand capable of binding a His-tagged molecule, said at least one ligand being a composite ligand which comprises an scaffold moiety attached to at least one chelator molecule capable of indirectly binding the His-Tagged molecule via a metal ion, said at least one ligand being attached to at least two coordinating moieties selected capable of directing the composition-of-matter to form a non-covalent complex when co-incubated with a coordinator ion or molecule. 
     
     
         34 . The composition-of-matter of  claim 33 , wherein said metal ion is different from said coordinator ion. 
     
     
         35 . A method of purifying at least one His-tagged molecule, the method comprising:
 (a) contacting the His-tagged molecule with the composition of  claim 33  so as to form a precipitate including said complex bound to the His-tagged molecule; and   (b) collecting said precipitate, thereby purifying the at least one molecule, target molecule or cell of interest.   
     
     
         36 . The method of  claim 35 , wherein said purifying is effected under homogeneous conditions. 
     
     
         37 . The method of  claim 35 , wherein said purifying is effected under heterogeneous conditions.