Gene coded for a MHC class I molecule, plasmid, expression system protein, multimer, reagent and kit to analyze a T cell frequency
A protein produced by an expression system that includes a nucleic acid sequence that encodes an MHC class I heavy chain. The MHC class I heavy chain comprises an alpha-1 helix and an alpha-2 helix. The nucleic acid sequence has a disulfide bridge formed between the alpha-1 helix and the alpha-2 helix in the MHC class I heavy chain. Amino acid 139 is substituted by a cysteine so as to provide Cys-139. Amino acid 84 is substituted by the cysteine so as to provide Cys-84 or amino acid 85 is substituted by the cysteine so as to provide Cys-85. The disulfide bridge is formed between the alpha-1 helix and the alpha-2 helix in the MHC class I heavy chain between Cys-139 and Cys-84 or between Cys-139 and Cys-85. The protein comprises an anchor element selected from a natural biotinylation sequence, a polyhistidine sequence, or a polyarginine sequence.
1. A protein produced by an expression system comprising a nucleic acid sequence that encodes an MHC class I heavy chain,
wherein,
the MHC class I heavy chain comprises an alpha-1 helix and an alpha-2 helix,
the nucleic acid sequence has a disulfide bridge formed between the alpha-1 helix and the alpha-2 helix in the MHC class I heavy chain,
the amino acid 139 is substituted by a cysteine so as to provide Cys-139,
the amino acid 84 is substituted by the cysteine so as to provide Cys-84 or the amino acid 85 is substituted by the cysteine so as to provide Cys-85,
the disulfide bridge is formed between the alpha-1 helix and the alpha-2 helix in the MHC class I heavy chain between Cys-139 and Cys-84 or between Cys-139 and Cys-85, and
the protein comprises an anchor element selected from a natural biotinylation sequence, a polyhistidine sequence, or a polyarginine sequence.
2. A protein conjugate comprising the protein as recited in claim 1 and a marker that is a fluorescent colorant.
3. An MHC class I multimer comprising at least two proteins, wherein at least one of the at least two proteins is the protein as recited in claim 1 .
4. The MHC class I multimer as recited in claim 3 , wherein the multimer is a tetramer or a pentamer.
5. The MHC class I multimer as recited in claim 3 , wherein the multimer comprises a marker disposed on the multimer, the marker being a fluorescent colorant.
6. The MHC class I multimer as recited in claim 3 , wherein the multimer comprises an anchor element selected from a biotin molecule, a polyhistidine sequence, or a polyarginine sequence.
7. A reagent comprising:
at least one of the protein as recited in claim 1 and the MHC class I multimer as recited in claim 3 ; and
a peptide capable of binding to an MHC class 1 complex comprising said MHC class I heavy chain.
8. A kit for analyzing a T-cell frequency, the kit comprising:
a first storage means comprising at least one of the protein as recited in claim 1 and the multimer as recited in claim 3 ; and
a second storage means comprising a peptide capable of binding to an MHC class 1 complex comprising said MHC class I heavy chain,
wherein a contents of the first storage means and the second storage means are configured to be combined.
9. A protein conjugate comprising the protein as recited in claim 1 and a marker, wherein the marker is a fluorescent colorant or a biotin molecule.