Methods for separating molecules

Abstract

The present invention provides compositions and methods for the separation of metals or molecules such as polypeptides, nucleic acids, or endotoxins using a metal-modified solid support. The metals or molecules are isolated from a starting material using the modified solid supports of the invention. Also provided by the invention are kits that can be used in connection with the inventive methods.

1 . A method for isolating membrane-associated proteins from a starting material comprising
 (a) contacting the starting material with a composition under suitable conditions to form a complex between the membranes and the composition, wherein the starting material comprises an in vitro expression system comprising microsomal membrane vesicles, and wherein the composition comprises:   
       
         
           
           
               
               
           
         
       
       wherein X is a substituted or unsubstituted alkylene moiety, a substituted or unsubstituted aralkylene moiety, or a substituted or unsubstituted arylene moiety;
 R 1  is a hydrocarbon moiety, or a substituted hydrocarbon moiety; 
 R 2  and R 3  are independently selected from R 1 , a hydrocarbon moiety, a substituted hydrocarbon moiety, a halogen atom, a hydrogen atom, a hydroxy, a thiol, an amine, a silanol bond to the solid support, a bond to another silane ligand, or O—Si—Y 1 Y 2 Y 3 , wherein Y 1 , Y 2  and Y 3  are independently selected from a hydrocarbon moiety, or a substituted hydrocarbon moiety; and 
 R N  is NH 2 , NHR N1 , NR N1 R N2 , or NR N1 R N2 R N3 , wherein R N1 , R N2 , and R N3  are independently selected from a hydrocarbon moiety, a substituted hydrocarbon moiety, or a hydrogen atom. 
 
     
     
         2 . The method of  claim 1 , wherein R N1 , R N2 , and R N3  are independently selected from the group consisting of an alkyl moiety of up to six carbon atoms in a longest chain, a substituted alkyl moiety of up to six carbon atoms in a longest chain, and a hydrogen atom. 
     
     
         3 . The method of  claim 1 , further comprising contacting the complex of step (a) with a nonionic detergent. 
     
     
         4 . A method for separating target material from non-target material in a starting material comprising:
 (a) contacting the starting material with a composition to form a complex between the target material and the composition, wherein the composition comprises:   
       
         
           
           
               
               
           
         
       
       wherein X is a substituted or unsubstituted alkylene moiety, a substituted or unsubstituted aralkylene moiety, or a substituted or unsubstituted arylene moiety;
 R 1  is a hydrocarbon moiety, or a substituted hydrocarbon moiety; 
 R 2  and R 3  are independently selected from R 1 , a hydrocarbon moiety, a substituted hydrocarbon moiety, a halogen atom, a hydrogen atom, a hydroxy, a thiol, an amine, a silanol bond to the solid support, a bond to another silane ligand, or O—Si—Y 1 Y 2 Y 3 , wherein Y 1 , Y 2  and Y 3  are independently selected from a hydrocarbon moiety, or a substituted hydrocarbon moiety; and 
 R N  is NH 2 , NHR N1 , NR N1 R N2 , or NR N1 R N2 R N3 , wherein R N1 , R N2 , and R N3  are independently selected from a hydrocarbon moiety with up to a six-carbon main chain, a substituted hydrocarbon moiety with up to a six-carbon main chain, or a hydrogen atom; 
 wherein at least a portion of the non-target material does not form a complex with the composition, wherein the non-target material comprises a polypeptide containing a prosthetic heme group. 
 
     
     
         5 . The method of  claim 4 , wherein R N1 , R N2 , and R N3  are independently selected from the group consisting of an alkyl moiety of up to six carbon atoms in a longest chain, a substituted alkyl moiety of up to six carbon atoms in a longest chain, and a hydrogen atom. 
     
     
         6 . The method of  claim 4 , wherein the non-target material is selected from the group consisting of hemoglobin and myoglobin. 
     
     
         7 . A method for removing cells from a starting material comprising:
 (a) contacting the starting material with a composition under conditions suitable to form a complex between the cells and the composition, the composition comprising:   
       
         
           
           
               
               
           
         
       
       wherein X is a substituted or unsubstituted alkylene moiety, a substituted or unsubstituted aralkylene moiety, or a substituted or unsubstituted arylene moiety;
 R 1  is a hydrocarbon moiety, or a substituted hydrocarbon moiety; 
 R 2  and R 3  are independently selected from R 1 , a hydrocarbon moiety, a substituted hydrocarbon moiety, a halogen atom, a hydrogen atom, a hydroxy, a thiol, an amine, a silanol bond to the solid support, a bond to another silane ligand, or O—Si—Y 1 Y 2 Y 3 , wherein Y 1 , Y 2  and Y 3  are independently selected from a hydrocarbon moiety, or a substituted hydrocarbon moiety; and 
 R N  is NH 2 , NHR N1 , NR N1 R N2 , or NR N1 R N2 R N3 , wherein R N1 , R N2 , and R N3  are independently selected from a hydrocarbon moiety, a substituted hydrocarbon moiety, or a hydrogen atom. 
 
     
     
         8 . The method of  claim 7 , wherein R N1 , R N2 , and R N3  are independently selected from the group consisting of an alkyl moiety of up to six carbon atoms in a longest chain, a substituted alkyl moiety of up to six carbon atoms in a longest chain, and a hydrogen atom. 
     
     
         9 . The method of  claim 7 , wherein R N1 , R N2 , and R N3  are independently selected from an alkyl moiety of up to six carbon atoms in a longest chain, a substituted alkyl moiety of up to six carbon atoms in a longest chain, and a hydrogen atom. 
     
     
         10 . The method of  claim 7 , wherein the conditions comprise the presence of methanol, ethanol, or isopropanol in a concentration of at least about 1% (v/v). 
     
     
         11 . The method of  claim 7 , wherein the conditions comprise the presence of isopropanol in a concentration of at least about 15% (v/v). 
     
     
         12 . The method of  claim 7 , wherein the cells are bacterial cells.