Abstract: The present invention addresses the problem of providing: a fusion protein or conjugated protein having excellent cell membrane permeability, containing a partial peptide derived from human, and suitable for intracellular delivery; an intracellular delivery carrier comprising such a fusion protein or conjugated protein; a partial peptide; a cell membrane permeation enhancer comprising the partial peptide; DNA; and a vector. The fusion protein or conjugated protein has a partial peptide comprising at least seven consecutive amino acid residues of an amino acid sequence encoded by a predetermined DNA, and a ligand directly or indirectly bound to the partial peptide and having the capability of binding to cell surfaces. The ligand is preferably an antibody. The intracellular delivery carrier comprises the fusion protein or conjugated protein. The cell membrane permeation enhancer comprises the partial peptide.

Abstract: The present invention addresses the problem of providing: a fusion protein or conjugated protein having excellent cell membrane permeability, containing a partial peptide derived from human, and suitable for intracellular delivery; an intracellular delivery carrier comprising such a fusion protein or conjugated protein; a partial peptide; a cell membrane permeation enhancer comprising the partial peptide; DNA; and a vector. The fusion protein or conjugated protein has a partial peptide comprising at least seven consecutive amino acid residues of an amino acid sequence encoded by a predetermined DNA, and a ligand directly or indirectly bound to the partial peptide and having the capability of binding to cell surfaces. The ligand is preferably an antibody. The intracellular delivery carrier comprises the fusion protein or conjugated protein. The cell membrane permeation enhancer comprises the partial peptide.

Abstract: A translation template comprising an ORF region coding for a protein, a 5? untranslated region comprising a transcription promoter and a translation enhancer and locating on the 5? side of the ORF region, and a 3? end region comprising a poly-A sequence and locating on the 3? side of the ORF region, is expressed in a translation system in the presence of an agent for modifying a C-terminal of a protein, which comprises an acceptor portion having a group capable of binding to a protein through a transpeptidation reaction in a protein translation system and a modifying portion comprising a nonradioactive modifying substance linked to the acceptor portion via a nucleotide linker, to cause protein synthesis and the synthesized protein is purified. Thus, the yield of modified protein in a method of modifying C-terminal of protein is improved and detection of protein interaction based on various intermolecular interaction detection methods is realized at an improved level.

Abstract: A method for screening a nucleic acid library for a nucleic acid encoding a protein that interacts with a target substance, which comprises: the step of producing a library of assigning molecules each comprising a protein and a nucleic acid encoding the protein linked to each other via a linker cleavable under a condition that does not change a nucleotide sequence of the nucleic acid; the step of mixing the library of assigning molecules and the target substance; the step of separating an assigning molecule binding to the target substance; the step of cleaving a linker of the separated assigning molecule under a condition that does not change a nucleotide sequence of the nucleic acid to release the nucleic acid; and the step of collecting the released nucleic acid. By this method, screening for an assigning molecule that specifically binds to a target substance can be conducted with high efficiency.

Abstract: The object of the present invention is to utilize, as a sensor protein, a molecular recognizing ability of a protein that scarcely undergoes any structural change by the binding of a target substance. According to the present invention, there is provided a sensor protein comprising an insert-type fusion protein composed of a reporter protein and a biding protein wherein said binding protein is inserted into the amino acid sequence of said reporter protein.

Abstract: The object of the present invention is to utilize, as a sensor protein, a molecular recognizing ability of a protein that scarcely undergoes any structural change by the binding of a target substance. According to the present invention, there is provided a sensor protein comprising an insert-type fusion protein composed of a reporter protein and a biding protein wherein said binding protein is inserted into the amino acid sequence of said reporter protein.

Abstract: A translation template comprising an ORF region coding for a protein, a 5? untranslated region comprising a transcription promoter and a translation enhancer and locating on the 5? side of the ORF region, and a 3? end region comprising a poly-A sequence and locating on the 3? side of the ORF region, is expressed in a translation system in the presence of an agent for modifying a C-terminal of a protein, which comprises an acceptor portion having a group capable of binding to a protein through a transpeptidation reaction in a protein translation system and a modifying portion comprising a nonradioactive modifying substance linked to the acceptor portion via a nucleotide linker, to cause protein synthesis and the synthesized protein is purified. Thus, the yield of modified protein in a method of modifying C-terminal of protein is improved and detection of protein interaction based on various intermolecular interaction detection methods is realized at an improved level.