Abstract: A method for preparing foreign protein in yeast using an expression recombinant DNA comprising DNA encoding the serum albumin signal peptide adjacent to DNA encoding the foreign protein is disclosed.

Abstract: Alkaline protease which has leucine or isoleucine in the place of valine at the amino acid number 40 of wild type alkaline protease, a gene encoding the amino acid sequence of alkaline protease which has the substitution as described above, a recombinant DNA comprising said gene, a method of producing the above described alkaline protease, and a DNA fragment used for the expression of a gene.

Abstract: A CSF-1 gene promoter region is disclosed. This nucleotide base sequence is useful as a promoter for gene expression in animal cells.

Abstract: A human prourokinase mutant in which the entire or a partial epidermal growth factor domain of human prourokinase is deleted or a partial epidermal growth factor domain of human prourokinase is replaced by one or more different amino acid residues, said mutant having a longer blood half-life than naturally occurring human prourokinase while retaining prourokinase enzymatic activity. In this human prourokinase mutant the region selected from the group consisting of: (a) from asparagine (10) to cysteine (42); (b) from asparagine (10) to aspartic acid (45); and (c) from asparagine (10) to threonine (49) is missing.

Abstract: A DNA sequence of the yeast glyceraldehyde-3-phosphate dehydrogenase (GAP-DH) promoter and a process for preparing a heterologous protein utilizing said DNA sequence as a promoter are disclosed, said GAP-DH promoter comprising a region upstream of an initiator codon of the GAP-DH protein up to -164 bp as a minimum unit. Since the GAP-DH promoter is small in size, a physiologically active substance can be expressed in yeasts effectively and recombination of DNA can be simplified.

Abstract: A method of producing a heterologous protein in yeast is disclosed, which comprises transforming a yeast Saccharomyces cerevisiae with recombinant DNA comprising a promoter selected from the group consisting of a yeast promoter or a hybrid promoter derived from a yeast promoter, particularly a hybrid promoter containing the enhancer region of SV40 virus, and a gene coding for a heterologous protein such as HBsAg and Pre S-HBsAg, particularly full length Pre S-HBsAg culturing, the resulting transformed cells to express the gene coding the heterologous protein, and isolating the heterologous protein from the cultured medium. GAP-DH and PH05 promoters and miniaturized ones can be used as the yeast promoter. The expression of the full length Pre S-HBsAg is carried out in the same expression system as that for 2nd or 3rd Pre S-ABsAg.

Abstract: A recombinant plasmid wherein at least two DNA fragments containing a Baker gene and a Charlie gene of the yeast 2 .mu.m circular plasmid are incorporated into a plasmid containing genes encoding a physiologically active substance is disclosed. Also, a strain transformed by the recombinant plasmid is disclosed.

Abstract: A process for the purification of HBsAg is disclosed, which comprises adsorbing specifically on a carrier, in the presence of an inorganic salt in an amount of 5 to 25 W/V %, an HBsAg obtained by gene engineering.

Abstract: A live mumps vaccine can be stabilized to a great extent by adding in an amount, effective for stabilizing said vaccine, at least one stabilizer selected from the group consisting of albumin and gelatin.

Abstract: Interferon can be recovered simply by contacting an aqueous solution containing interferon which is induced and produced from cells of human origin capable of producing interferon, with a siliceous substance to adsorb interferon on it and eluting the adsorbed interferon with an aqueous solution containing a nonionic surfactant, preferably further containing an acriflavine such as acrinol.

Abstract: A process for recovering interferon which comprises contacting a solution containing an interferon produced by the induced cells of human origin with a water-insolubilized sulfated polysaccharide to allow the interferon to be adsorbed on the water-insolubilized sulfated polysaccharide and then selectively eluting the interferon with an aqueous solution of an inorganic salt.

Abstract: A process for recovering interferon which comprises contacting a solution containing an interferon produced by the induced cells of human origin with a water-insolubilized sulfated polysaccharide to allow the interferon to be adsorbed on the water-insolubilized sulfated polysaccharide and then selectively eluting the interferon with an aqueous solution of an inorganic salt.

Abstract: Double-stranded RNA synthesized using native human DNA as template is found to be an excellent interferon inducer with low toxicity in spite of homologous native to host cell. It is produced by reacting ATP, GTP, CTP and UTP with one another in the presence of a native human DNA as template by the catalytic action of an active RNA polymerase to form RNA and subjecting the resulting RNA to annealing by heating it at a temperature of 70.degree. to 100.degree. C. and gradually cooling to room temperature or below to form double-stranded regions between their molecules.