Abstract: The present invention relates in providing a process for recovering a soluble protein having a higher recovery rate by suppressing the aggregation of the protein when a denaturing agent is removed from the solubilization treatment solution containing a solubilized protein; and providing a process for removing a denaturing agent from the above solubilization treatment solution in which the aggregation of the protein is suppressed.

Abstract: An artificial operon comprising polynucleotides encoding each of DsbA, DsbB, DsbC and DsbD; an expression plasmid carrying the above artificial operon, usable for expression of DsbA, DsbB, DsbC and DsbD; a cotransformant harboring the above expression plasmid and an expression vector for a foreign protein; and a method for producing a foreign protein comprising culturing the cotransformant.

Abstract: A factor capable of efficiently regulating expression of an endoplasmic chaperone gene, a nucleic acid encoding it, a complementary strand nucleic acid thereof, a method for regulating expression of an endoplasmic reticulum chaperone gene, and a method for expressing a foreign gene is provided. The endoplasmic reticulum stress transcription factor is capable of regulating transcription-inducing activity, wherein the transcription-inducing activity is exhibited by an element having the nucleotide sequence shown in SEQ ID NO:1 or an element having a nucleotide sequence resulting from substitution of 1 to 3 bases with other bases in the nucleotide sequence as shown in SEQ ID NO:1.

Abstract: To provide a heat shock transcription factor (HSF) 2 binding factor, which can be involved in the transcriptional regulation of HSP70.2 playing an essential role in spermatogenesis; a DNA encoding the binding factor; an expression vector carrying the DNA; a transformant harboring the expression vector; a process for preparing a recombinant protein comprising the step of culturing the transformant; an antibody or a fragment thereof capable of specifically binding to the binding factor; an antisense DNA or antisense RNA complementary to the DNA; and an oligonudeotide probe or primer capable of specifically hybridizing to the DNA.

Abstract: An artificial operon comprising genes encoding each of a trigger factor, GroEL and GroES, an expression plasmid carrying the operon, an expression plasmid carrying a gene encoding the trigger factor, a cotransformant harboring an expression vector for a foreign protein and any one of the expression plasmids, and a method for producing a foreign protein comprising expressing a foreign protein by the use of the cotransformant, which are capable of expressing a foreign protein in a solubilized form and in a state of having a correct conformation.

Abstract: An artificial operon comprising polynucleotides encoding each of chaperones DnaK, DnaJ and GrpE; an expression plasmid carrying the operon; a cotransformant prepared by introducing the expression plasmid into E. coli together with a foreign protein expression vector; and a method for producing a foreign protein comprising using the cotransformant.

Abstract: A polypeptide obtainable by inducement under hypoxic conditions having a sequence comprising:(a) the amino acid sequence of SEQ ID NO:1 or 3 or a fragment thereof; (b) an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 2 or 4 or a fragment thereof; or (c) an amino acid sequence resulting from deletion, addition, insertion or substitution of one or more amino acids in the amino acid sequence of SEQ ID NO:1 or 3; a polynucleotide encoding the above polypeptide or the fragment thereof useful for producing the above polypeptide by a biotechnological technique; and an antibody or fragment thereof specifically binding the above polypeptide.

Abstract: A polypeptide obtainable by inducement under hypoxic conditions having a sequence comprising: (a) the amino acid sequence of SEQ ID NO:1 or 3 or a fragment thereof; (b) an amino acid sequence encoded by the nucleotide sequence of SEQ ID NO: 2 or 4 or a fragment thereof; or (c) an amino acid sequence resulting from deletion, addition, insertion or substitution of one or more amino acids in the amino acid sequence of SEQ ID NO:1 or 3; a polynucleotide encoding the above polypeptide or the fragment thereof useful for producing the above polypeptide by a biotechnological technique; and an antibody or fragment thereof specifically binding the above polypeptide.