Compositions and methods for the detection of zinc

Abstract

The invention relates generally to compositions and methods for the detection of zinc. In particular, compositions and methods are provided to detect changes in cellular zinc concentration and to correlate them to cellular phenomena.

We claim: 
     
         1 . A Zn-responsive probe which has the following chemical structure: 
       
         
           
           
               
               
           
         
         wherein each of said R 3 s are individually selected from: H, CH 3 , an alkyl group, an O-alkyl group, an N-alkyl group, a linker group, an attachment group, and a linker group attached to an attachment group; 
         wherein said R 1  is selected from: H, CH 3 , an alkyl group, a linker group, an attachment group, and a linker group attached to an attachment group; and 
         wherein said R 2  is a Zn binding group. 
       
     
     
         2 . The Zn-responsive probe of  claim 1 , wherein said Zn binding group has the following formula: 
       
         
           
           
               
               
           
         
       
       wherein A and B each seperately comprise at least one moiety selected from an amine donor, an oxygen donor, and a sufur donor. 
     
     
         3 . The Zn-responsive probe of  claim 1 , wherein said Zn binding group has the following formula: 
       
         
           
           
               
               
           
         
       
       wherein A and B each seperately comprise at least one moiety selected from a pyridine, an amine, an imidazole, a sulfonamide, a carboxylate, a phenol, an ether, an alcohol, a thiol, a thioether, and a thiophene. 
     
     
         4 . The Zn-responsive probe of  claim 1 , wherein said Zn binding group has the following formula: 
       
         
           
           
               
               
           
         
       
       or a derivative of said formula that is able to chelate zinc. 
     
     
         5 . The Zn-responsive probe of  claim 1 , wherein said chemical structure is as follows: 
       
         
           
           
               
               
           
         
       
     
     
         6 . The Zn-responsive probe of  claim 1 , wherein each of said R 3 s are CH 3 . 
     
     
         7 . The Zn-responsive probe of  claim 1 , wherein said R 1  is CH 3 . 
     
     
         8 . The Zn-responsive probe of  claim 1 , wherein said R 1  comprises an attachment group. 
     
     
         9 . A method of non-invasively detecting Zn release and/or uptake by a cell or cells comprising:
 a) contacting a sample comprising a cell or cells with a composition comprising a Zn-responsive probe, wherein said Zn-responsive probe is present in said composition at a concentration between 1×10 −5  M and 1×10 −9  M;   b) detecting the signal emitted by the signaling moiety over time; and   c) correlating signal emitted with Zn concentration.   
     
     
         10 . The method of  claim 9 , wherein the sample comprises one or more oocytes. 
     
     
         11 . The method of  claim 9 , wherein the Zn-responsive probe is attached to a surface. 
     
     
         12 . The method of  claim 9 , wherein the concentration of said Zn-responsive probe is between 1×10 −7  and 1×10 −8  M. 
     
     
         13 . The method of  claim 9 , wherein said cell comprises a metaphase-II-arrested oocyte, wherein said method further comprises a step before step b) of contacting the sample with sperm, and wherein said detecting the signal comprises detecting a significant increase in extracellular Zn concentration based on a change in the signal of the Zn-responsive probe. 
     
     
         14 . The method of  claim 13 , wherein said correlating said signal comprises correlating the significant increase in extracellular Zn concentration to fertilization of the oocyte by the sperm. 
     
     
         15 . The method of  claim 14 , further comprising removing the oocyte from the Zn-responsive probe, and implanting the fertilized oocyte into a subject. 
     
     
         16 . The method of  claim 9 , wherein the Zn-responsive probe has the chemical structure shown in  claim 1 . 
     
     
         17 . A method of evaluating the quality of an oocyte for fertilization comprising:
 a) contacting a surface with a sample comprising the oocyte, wherein said surface displays a plurality of Zn-responsive probes;   b) detecting the signal emitted by the Zn-responsive probes over time; and   c) correlating the signal emitted with extracellular Zn concentration, wherein a decrease in extracellular Zn is indicative of an oocyte that is ready for fertilization.   
     
     
         18 . The method of  claim 17 , where the oocyte is in prophase-1-arrest upon contacting with the surface. 
     
     
         19 . The method of  claim 17 , wherein the Zn-responsive probe is attached to a surface. 
     
     
         20 . The method of  claim 19 , wherein the Zn-responsive probe has the chemical structure shown in  claim 1 .