Affinity tag nucleic acid and protein compositions, and processes for using same

Abstract

The present invention concerns compositions and processes that use affinity tags for isolating, and detecting or quantifying analytes, including nucleic acids, proteins and polypeptides. Compositions include nucleic acid compositions and protein compositions with affinity binding pairs, including metal binding peptides and immobilized metals, or peptide affinity groups.

1 . A composition which comprises a nucleic acid and one member of an affinity binding pair, wherein said member is attached to one or more nucleotides of said nucleic acid through a phosphate or sugar of said nucleotide or nucleotides. 
     
     
         2 . The composition of  claim 1 , wherein said affinity binding pair comprises: (a) a metal binding peptide and an immobilized metal, or (b) a peptide affinity group. 
     
     
         3 . The composition of  claim 2 , wherein said metal binding peptide comprises any of the amino acid sequences: oligohistidine, HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         4 . The composition of  claim 2 , wherein said immobilized metal comprises nickel, copper, cobalt or zinc. 
     
     
         5 . The composition of  claim 2 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         6 . The composition of  claim 1 , wherein said member is attached to said nucleotide or nucleotides through a linker arm. 
     
     
         7 . The composition of  claim 1 , further comprising one or more energy transfer donors. 
     
     
         8 . The composition of  claim 1 , further comprising one or more energy transfer acceptors. 
     
     
         9 . A chimeric nucleic acid comprising at least two portions, a first portion comprising a nucleic acid complementary to a nucleic acid sequence of interest, and a second portion comprising a metal binding peptide, wherein said metal binding peptide is attached to one or more nucleotides of the nucleic acid in said first portion through a sugar or phosphate of said nucleotide or nucleotides. 
     
     
         10 . The composition of  claim 9 , wherein said metal binding peptide comprises any of the amino acid sequences: oligohistidine, HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         11 . The composition of  claim 9 , wherein said metal or metals are attached to said nucleotide or nucleotides through a linker arm. 
     
     
         12 . The composition of  claim 9 , wherein said metal binding peptide has an affinity for nickel, copper, cobalt or zinc. 
     
     
         13 . The composition of  claim 9 , further comprising one or more energy transfer donors. 
     
     
         14 . The composition of  claim 9 , further comprising one or more energy transfer acceptors. 
     
     
         15 . A chimeric nucleic acid comprising at least two portions, a first portion comprising a nucleic acid complementary to a nucleic acid sequence of interest, and a second portion comprising one member of a peptide affinity group, wherein said member is attached to one or more nucleotides of said nucleic acid in said first portion. 
     
     
         16 . The chimeric nucleic acid of  claim 15 , wherein said peptide affinity binding group comprises any of the pairs: S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         17 . The composition of  claim 15 , wherein said member is attached to said nucleotide or nucleotides through a linker arm. 
     
     
         18 . The composition of  claim 15 , further comprising one or more energy transfer donors. 
     
     
         19 . The composition of  claim 15 , further comprising one or more energy transfer acceptors. 
     
     
         20 . A process for isolating one or more species of a nucleic acid of interest, comprising the steps of:
 providing:
 a sample containing or suspected of containing said nucleic acid of interest, 
 a composition which comprises a nucleic acid portion and a first member of an affinity binding pair, wherein said nucleic acid portion comprises sequences complementary to said nucleic acid species of interest, wherein said affinity binding pair comprises (a) a metal binding peptide and an immobilized metal, or (b) a peptide affinity group; and wherein said first member of the affinity binding pair is attached to one or more nucleotides in said nucleic acid portion; and 
 a matrix comprising a second member of said affinity binding pair; 
   hybridizing said composition with any nucleic acid of interest contained in said sample to form a first complex;   contacting said first complex with said matrix to form a second complex by means of a binding interaction between said first member and said second member of the affinity binding pair; and   separating bound from unbound material, thereby isolating said nucleic acid species of interest.   
     
     
         21 . The process of  claim 20 , wherein said metal binding peptide comprises any of the amino acid sequences: oligohistidine, HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7). KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         22 . The process of  claim 20 , wherein said immobilized metal comprises nickel, copper, cobalt or zinc. 
     
     
         23 . The process of  claim 20 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         24 . The process of  claim 20 , wherein said first member of said affinity binding pair is attached to said one or more nucleotides through a linker arm. 
     
     
         25 . The process of  claim 20 , wherein in said separating step the portion of said sample that remains unbound to said matrix comprises said nucleic acid species of interest. 
     
     
         26 . The process of  claim 20 , wherein the portion of said sample that remains bound to said matrix comprises said nucleic acid species of interest. 
     
     
         27 . The process of  claim 20 , further comprising one or more washing steps. 
     
     
         28 . A process for detecting the presence or quantity of a nucleic acid of interest, comprising the steps of:
 providing:
 a sample containing labeled nucleic acids, 
 a composition comprising a nucleic acid portion and a first member of an affinity binding pair, wherein said nucleic acid portion comprises sequences complementary to said nucleic acid of interest, and 
 a matrix comprising a second member of said affinity binding pair; 
 wherein said affinity binding pair comprises (a) a metal binding peptide and an immobilized metal, or (b) a peptide affinity group; and wherein said first member of the affinity binding pair is attached to one or more nucleotides of said nucleic acid portion; and 
   hybridizing said composition with any nucleic acid of interest contained in said sample to form a first complex;   contacting said first complex with said matrix to form a second complex by means of a binding interaction between said first member and said second member of said affinity binding pair; and   washing said matrix to remove unhybridized nucleic acids from said matrix; and detecting or quantifying said nucleic acid of interest by means of detecting or quantifying a signal from said labels.   
     
     
         29 . The process of  claim 28 , wherein said metal binding peptide comprises any of the amino acid sequences: oligohistidine, HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         30 . The process of  claim 28 , wherein said immobilized metal comprises nickel, copper, cobalt or zinc. 
     
     
         31 . The process of  claim 28 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         32 . The process of  claim 28 , wherein said first member of the affinity binding pair is attached to said nucleotide or nucleotides through a linker arm. 
     
     
         33 . The process of  claim 28 , wherein said labeled nucleic acids in the sample comprise one or more energy transfer donors and wherein said composition comprise one or more energy transfer acceptors. 
     
     
         34 . The process of  claim 28 , wherein said labeled nucleic acids in the sample comprise one or more energy transfer acceptors and wherein said composition comprise one or more energy transfer donors. 
     
     
         35 . The process of  claim 28 , wherein said labeled nucleic acids comprise labels that are fluorescently, chemiluminescently, colorimetrically or enzymatically detectable. 
     
     
         36 . The process of  claim 28 , further comprising a step of releasing said second complex from said matrix prior to said detecting step. 
     
     
         37 . A process for detecting the presence or quantity of a nucleic acid of interest, comprising the steps of:
 providing:
 a sample containing or suspected of containing said nucleic acid of interest; 
 a labeled probe complementary to said nucleic acid of interest; 
 a composition comprising a nucleic acid portion and a first member of an affinity binding pair, wherein said nucleic acid portion comprises sequences complementary to said nucleic acid of interest, wherein said affinity binding pair comprises (a) a metal binding peptide and an immobilized metal, or (b) a peptide affinity group, and wherein said first member of the affinity binding pair is attached to one or more nucleotides of said nucleic acid portion through a sugar, phosphate or base of said nucleotide or nucleotides; and 
 a matrix comprising a second member of said affinity binding pair; 
   hybridizing any nucleic acids of interest in said sample with labeled probe and said composition to form a first complex;   contacting said first complex with said matrix to form a second complex by means of a binding interaction between said first member and said second member of said affinity binding pair;   washing said matrix to remove unbound materials from said sample; and detecting or quantifying said nucleic acid of interest by means of detecting or quantifying a signal from said labels.   
     
     
         38 . The process of  claim 37 , wherein said metal binding peptide (a) comprises any of the amino acid sequences: oligohistidine, HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         39 . The process of  claim 37 , wherein said immobilized metal comprises nickel, copper, cobalt or zinc. 
     
     
         40 . The process of  claim 37 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         41 . The process of  claim 37 , wherein said first member of the affinity binding pair is attached to said nucleotide or nucleotides through a linker arm. 
     
     
         42 . The process of  claim 37 , wherein said labeled probes comprise one or more energy transfer donors and wherein said composition comprises one or more energy transfer acceptors. 
     
     
         43 . The process of  claim 37 , wherein said labeled probes comprise one or more energy transfer acceptors and wherein said composition comprises one or more energy transfer donors. 
     
     
         44 . The process of  claim 37 , wherein said labeled probes comprise one or more energy transfer donors and wherein the nucleic acids in said sample have been labeled with one or more energy transfer acceptors. 
     
     
         45 . The process of  claim 37 , wherein said labeled probes comprise one or more energy transfer acceptors and wherein the nucleic acids in said sample have been labeled with one or more energy transfer donors. 
     
     
         46 . The process of  claim 37 , wherein said labeled nucleic acids are detected fluorescently, chemiluminescently, colorimetrically or enzymatically. 
     
     
         47 . The process of  claim 37 , further comprising a step of releasing said second complex from said matrix prior to said detecting step. 
     
     
         48 . A process for detecting the presence or quantity of a nucleic acid of interest, comprising the steps of:
 providing:
 a sample containing or suspected of containing said nucleic acid of interest; 
 a probe complementary to said nucleic acid of interest and comprising two portions, wherein a first comprises sequences complementary to said nucleic acid of interest, and a second portion comprising a signal sequence; 
 a composition comprising a nucleic acid portion and a first member of an affinity binding pair, wherein said nucleic acid portion comprises sequences complementary to said nucleic acid of interest, wherein said affinity binding pair comprises (a) a metal binding peptide and an immobilized metal, or (b) a peptide affinity group, and wherein said first member of the affinity binding pair is attached to one or more nucleotides of said nucleic acid; and 
 a matrix comprising a second member of said affinity binding pair; 
   hybridizing any nucleic acids of interest in said sample with labeled probe and said composition to form a first complex;   contacting said first complex with said matrix to form a second complex by means of a binding interaction between said one or more binding partners and said affinity peptide;   washing said matrix to remove unbound materials from said sample; and detecting or quantifying said nucleic acid of interest by hybridizing labeled oligonucleotides complementary to said signal sequence.   
     
     
         49 . The process of  claim 48 , wherein said metal binding peptide comprises any of the amino acid sequences oligohistidine, HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         50 . The process of  claim 48 , wherein said immobilized metal comprises nickel, copper, cobalt or zinc. 
     
     
         51 . The process of  claim 48 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         52 . The process of  claim 48 , wherein said labeled oligonucleotides are detected fluorescently, chemiluminescently, colorimetrically or enzymatically. 
     
     
         53 . The process of  claim 48 , wherein said signal sequence comprises a homopolymeric sequence. 
     
     
         54 . The process of  48 , wherein said signal sequence comprises a heterologous sequence, wherein said heterologous sequence is neither identical or complementary to said nucleic acid of interest. 
     
     
         55 . A fusion protein comprising a biologically active polypeptide or protein and at least one affinity peptide attached to the amino-terminus or the carboxyl-terminus of said biologically active polypeptide or protein, wherein said affinity peptide comprises at least a portion of the amino acid sequence of kininogen, said portion comprising a metal binding peptide. 
     
     
         56 . A fusion protein comprising a biologically active polypeptide or protein and an affinity peptide attached at the amino-terminus and an affinity peptide attached at the carboxyl-terminus of said biologically active polypeptide or protein, wherein said affinity peptides comprise at least a portion of the amino acid sequence kininogen, said portion comprising a metal binding peptide. 
     
     
         57 . The fusion protein of  claim 55  or  56 , wherein said affinity peptide comprises the sequence
 GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10),   or a portion thereof.   
     
     
         58 . The fusion protein of  claim 55  or  56 , wherein said kininogen comprises human kininogen. 
     
     
         59 . The fusion protein of  claim 55  or  56 , wherein said fusion protein comprises an amino acid sequence between said biologically active polypeptide or protein and said affinity peptides, wherein said sequence is recognizable by a protease. 
     
     
         60 . The fusion protein of  claim 59 , wherein said protease comprises enterokinase or coagulation factor X a . 
     
     
         61 . The fusion protein of  claim 55 , wherein said affinity peptide binds nickel, copper, cobalt or zinc. 
     
     
         62 . A fusion protein comprising an antibody linked by its amino- and/or carboxyl-terminus to one or two affinity peptides, wherein said affinity peptide binds to a metal, and wherein said antibody has an affinity to an epitope on a different antibody. 
     
     
         63 . The fusion protein of  claim 62 , wherein said affinity peptide comprises oligohistidine or an oligopeptide comprising the sequence HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         64 . A process for modifying a protein of interest, said process comprising the steps of:
 providing (i) a nucleic acid that codes for said protein of interest;
 (ii) a nucleic acid that codes for a portion of the amino acid sequence of kininogen, wherein said portion codes for a metal binding peptide; and 
 (iii) an expression vector; 
   adding said nucleic acid (ii) to said nucleic acid (i) to generate a nucleic acid coding for a fusion protein; and   inserting said nucleic acid coding for said fusion protein into said expression vector (iii), thereby generating a vector that expresses said modified protein of interest.   
     
     
         65 . The process of  claim 64 , wherein said expression vector (iii) comprises a mammalian expression vector, a bacterial expression vector, an insect cell expression vector and a yeast expression vector. 
     
     
         66 . The process of  claim 64 , wherein said expression vector (iii) comprises a plasmid or viral vector. 
     
     
         67 . A process for isolating a protein of interest, said process comprising the steps of:
 providing: (i) a nucleic acid that codes for said protein of interest;
 (ii) a nucleic acid that codes for a portion of the amino acid sequence of kininogen, wherein said portion codes for a metal binding peptide; 
 (iii) an expression vector; and 
 (iv) a metal-modified matrix; 
   adding said nucleic acid (ii) to said nucleic acid (i) to generate a nucleic acid coding for a fusion protein;   inserting said nucleic acid coding for said fusion protein into said expression vector (iii), thereby generating a vector that expresses said protein of interest; and   purifying said modified protein of interest by binding said protein of interest to said metal-modified matrix (iv).   
     
     
         68 . The process of  claim 67 , wherein said expression vector (iii) comprises a mammalian expression vector, a bacterial expression vector, an insect cell expression vector and a yeast expression vector. 
     
     
         69 . The process of  claim 67 , wherein said expression vector (iii) comprises a plasmid or viral vector. 
     
     
         70 . The process of  claim 67 , wherein said purifying step, the metal-modified matrix comprises a chromatographic column or a microtitre plate. 
     
     
         71 . A fusion protein comprising an antibody and at least one affinity peptide attached to the amino terminus or the carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody. 
     
     
         72 . A fusion protein comprising an antibody and an affinity peptide attached to the amino terminus and an affinity peptide attached to carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody. 
     
     
         73 . The fusion protein of  claim 71 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         73 . The fusion protein of  claim 62 , wherein said metal binding peptide comprises oligohistidine or an oligopeptide comprising the sequence HGGHHG (SEQ ID NO: 1, SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         74 . A process for isolating an analyte of interest, said process comprising the steps of:
 providing
 (i) a sample containing or suspected of containing said analyte of interest; 
 (ii) a first antibody having an affinity for said analyte; 
 (iii) a fusion antibody comprising:
 (a) an antibody and at least one affinity peptide attached to the amino terminus or the carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody; or 
 (b) an antibody and an affinity peptide attached to the amino terminus and an affinity peptide attached to carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody; and 
 
 (iv) a matrix comprising a metal or a second member of said affinity peptide group. 
   contacting said sample with said first antibody, thereby forming a first complex between said first antibody and any analyte present in said sample;   contacting said first complex with said fusion antibody, thereby forming a second complex between said first complex and said fusion antibody;   contacting said second complex with said matrix to bind said second complex to said matrix;   removing unbound material from said matrix, and   releasing said analyte of interest from said second complex, thereby isolating said analyte of interest.   
     
     
         75 . The process of  claim 74 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         76 . The process of  claim 74 , wherein said metal binding peptide comprises oligohistidine or an oligopeptide comprising the sequence HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         77 . A process for detecting or quantifying an analyte of interest, said process comprising the steps of:
 providing
 (i) a labeled sample containing or suspected of containing labeled analyte of interest; 
 (ii) a first antibody having an affinity for said analyte; 
 (iii) a fusion antibody comprising:
 (a) an antibody and at least one affinity peptide attached to the amino terminus or the carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody; or 
 (b) an antibody and an affinity peptide attached to the amino terminus and an affinity peptide attached to carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody; and 
 
 (iv) a matrix comprising a metal or a second member of said affinity peptide group; 
   contacting said sample with said first antibody, thereby forming a first complex between said first antibody and any analyte present in said sample;   contacting said first complex with said fusion antibody, thereby forming a second complex between said first complex and said fusion antibody;   contacting said second complex with said matrix to bind said second complex to said matrix;   removing unbound material from said matrix; and   detecting or quantifying said labeled analytes bound to said matrix by means of detecting or quantifying a signal from said labels.   
     
     
         78 . The process of  claim 77 , wherein said peptide affinity group comprises S-protein and S-peptide, GST and GSH, PKA peptide and PKA, HA peptide and HA, KSI and oligo PHE, KSI and oligo Leu, oligo Arg and oligo Glu, or oligo Arg and oligo Asp. 
     
     
         79 . The process of  claim 77 , wherein said metal binding peptide comprises oligohistidine or an oligopeptide comprising the sequence HGGHHG (SEQ ID NO: 1), SPHHG (SEQ ID NO: 2), SPHHGGSPHHG (SEQ ID NO: 3), HPHHG (SEQ ID NO: 4), HPHHGGHPHHG (SEQ ID NO: 5), SPHHGGHPHHG (SEQ ID NO: 6), HPHHGGSPHHG (SEQ ID NO: 7), KDHLIHNVHKEEHAHAHNK (SEQ ID NO: 8), GHGLGHGHEQQHGLGHGHK (SEQ ID NO: 10) or HGLGHGHEQQHGLGHGH (SEQ ID NO: 9). 
     
     
         80 . The process of  claim 77 , wherein said analyte of interest comprises a protein or polypeptide. 
     
     
         81 . The process of  claim 77 , further comprising the step of releasing said analyte of interest from said second complex prior to said detecting or quantifying step. 
     
     
         82 . The process of  claim 77 , wherein said labeled analytes are detected fluorescently, chemiluminescently, colorimetrically or enzymatically. 
     
     
         83 . A process for detecting or quantifying an analyte of interest, said process comprising the steps of:
 providing
 (i) a labeled sample containing or suspected of containing labeled analytes of interest; 
 (ii) a first antibody having an affinity for said analyte; 
 (iii) a fusion antibody comprising:
 (a) an antibody and at least one affinity peptide attached to the amino terminus or the carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody; or 
 (b) an antibody and an affinity peptide attached to the amino terminus and an affinity peptide attached to carboxyl terminus of said antibody, wherein said affinity peptide comprises a metal binding peptide or is one member of a peptide affinity group, wherein said antibody has an affinity for a different antibody; and 
 
 (iv) a matrix comprising a metal or a second member of said affinity peptide group. 
   forming a first complex among said matrix, said fusion antibody and said first antibody;   contacting said first complex with said labeled sample, thereby forming a second complex between said first complex and any labeled analytes that may be present in said sample;   removing unbound material from said matrix; and   detecting or quantifying said labeled analytes bound to said matrix by means of detecting or quantifying a signal from said labels.   
     
     
         84 . The process of  claim 83 , wherein said matrix comprises an array of different first antibodies, thereby detecting or quantifying multiple analytes of interest. 
     
     
         85 . The process of  claim 83 , wherein said labeled analytes are detected fluorescently, chemiluminescently, colorimetrically or enzymatically.