Abstract:
A method is provided for detecting a protein using a cyclodextrin covalently linked to at least one label. The cyclodextrin can associate with the protein by sequestering an aromatic amino acid side-chain of the protein in its hydrophobic cavity. After contacting the protein with the cyclodextrin, the label can be detected directly or can undergo a chemical interaction with a reagent to form a detectable product. The label can include an indole moiety, which can react with a halo-substituted organic compound upon exposure to UV light and thereby be rendered fluorescent. Alternatively, the label can include a biotin moiety, which can bind to a binding partner such as avidin, or variants thereof, to form a detectable molecular complex. A labeled cyclodextrin can be used in the present methods to detect a protein of interest in an electrophoresis gel or on a blotting membrane. Aromatic amino acid residues of the protein, in particular tryptophan, remain protected from chemical modification due to sequestration by the cyclodextrin, making these methods compatible with downstream applications that require intact protein. Also provided herein are compositions, kits, and electrophoresis gels for use in detecting proteins.
Abstract:
Proteins that are electrophoretically separated in a gel are derivatized to produce fluorescent emissions by incorporating halo-substituted organic compounds into one or both of the electrode buffer solutions at the two ends of the gel. The halo-substituted compounds used are ones that bear an electric charge at the pH of the buffer solutions and gel, and the polarity of the charge on the compounds is such that the compounds migrate from the electrode buffer into the gel under the electrophoretic influence concurrently with the migration of the proteins into the gel. Once the proteins are separated and distributed within the gel and the gel is fully penetrated with the halo-substituted compounds, the gel is irradiated with ultraviolet light to induce a reaction between the halo-substituted compounds and the proteins through the tryptophan residues on the proteins, producing fluorescent reaction products.
Abstract:
Proteins that are electrophoretically separated in a gel are derivatized to produce fluorescent emissions by incorporating halo-substituted organic compounds into one or both of the electrode buffer solutions at the two ends of the gel. The halo-substituted compounds used are ones that bear an electric charge at the pH of the buffer solutions and gel, and the polarity of the charge on the compounds is such that the compounds migrate from the electrode buffer into the gel under the electrophoretic influence concurrently with the migration of the proteins into the gel. Once the proteins are separated and distributed within the gel and the gel is fully penetrated with the halo-substituted compounds, the gel is irradiated with ultraviolet light to induce a reaction between the halo-substituted compounds and the proteins through the tryptophan residues on the proteins, producing fluorescent reaction products.
Abstract:
A method is provided for detecting a protein using a cyclodextrin covalently linked to at least one label. The cyclodextrin can associate with the protein by sequestering an aromatic amino acid side-chain of the protein in its hydrophobic cavity. After contacting the protein with the cyclodextrin, the label can be detected directly or can undergo a chemical interaction with a reagent to form a detectable product. The label can include an indole moiety, which can react with a halo-substituted organic compound upon exposure to UV light and thereby be rendered fluorescent. Alternatively, the label can include a biotin moiety, which can bind to a binding partner such as avidin, or variants thereof, to form a detectable molecular complex. A labeled cyclodextrin can be used in the present methods to detect a protein of interest in an electrophoresis gel or on a blotting membrane. Aromatic amino acid residues of the protein, in particular tryptophan, remain protected from chemical modification due to sequestration by the cyclodextrin, making these methods compatible with downstream applications that require intact protein. Also provided herein are compositions, kits, and electrophoresis gels for use in detecting proteins.
Abstract:
Proteins that are electrophoretically separated in a gel are derivatized to produce fluorescent emissions by incorporating halo-substituted organic compounds into one or both of the electrode buffer solutions at the two ends of the gel. The halo-substituted compounds used are ones that bear an electric charge at the pH of the buffer solutions and gel, and the polarity of the charge on the compounds is such that the compounds migrate from the electrode buffer into the gel under the electrophoretic influence concurrently with the migration of the proteins into the gel. Once the proteins are separated and distributed within the gel and the gel is fully penetrated with the halo-substituted compounds, the gel is irradiated with ultraviolet light to induce a reaction between the halo-substituted compounds and the proteins through the tryptophan residues on the proteins, producing fluorescent reaction products.
Abstract:
Proteins that are electrophoretically separated in a gel are derivatized to produce fluorescent emissions by incorporating halo-substituted organic compounds into one or both of the electrode buffer solutions at the two ends of the gel. The halo-substituted compounds used are ones that bear an electric charge at the pH of the buffer solutions and gel, and the polarity of the charge on the compounds is such that the compounds migrate from the electrode buffer into the gel under the electrophoretic influence concurrently with the migration of the proteins into the gel. Once the proteins are separated and distributed within the gel and the gel is fully penetrated with the halo-substituted compounds, the gel is irradiated with ultraviolet light to induce a reaction between the halo-substituted compounds and the proteins through the tryptophan residues on the proteins, producing fluorescent reaction products.