Abstract: The heterologous expression of the reverse transcriptase from the Avian Myeloblastosis Virus (AMV-RT) in prokaryotic cells and in particular Escherichia coli (E. coli) is described in the present invention. The invention also includes certain measures to simplify the purification of the heterodimeric AMV-RT.

Abstract: This invention involves a process for selecting and producing eukaryotic alkaline phosphatase in yeast. Yeast cells are subjected to multiple transformations using a vector comprising a first resistance marker gene and the alkaline phosphatase gene. Those strains that grow in media containing the first resistance marker are further transformed using a vector comprising a second selection marker gene and the alkaline phosphatase gene. Transformants that grow in media containing the second selection marker are selected for expressing the eukaryotic alkaline phosphatase.

Abstract: A method is provided for the production of a bovine pancreatic protein with a specific desoxyribonuclease activity of at least 6,000 units per mg of protein. Methylotrophic yeast is used as a heterologous host organism. The bovine pancreatic protein is secreted into the growth medium from which it is purified.

Abstract: According to the invention, the desoxyribonuclease with increased thermolability is a variant, by way of amino acid substitution, of bovine pancreatic desoxyribonuclease I. The variant protein retains desoxyribonuclease activity. Moreover, the specific desoxyribonuclease activity of the variant of bovine pancreatic desoxyribonuclease I is approximately zero units per mg of protein following heating of the variant of bovine pancreatic desoxyribonuclease I for about 5 min at a temperature below 95° C. In addition, the variant of bovine pancreatic desoxyribonuclease I has no measurable ribonuclease activity.

Abstract: The present invention concerns a method for producing recombinant trypsin from porcine pancreas in Pichia pastoris which is soluble and secreted into the culture medium, whereby expression at pH 3.0-4.0 substantially prevents activation of trypsinogen to &bgr;-trypsin and autolysis of &bgr;-trypsin by &agr;-trypsin into &egr;-trypsin and from there into inactive peptides.

Abstract: The invention concerns a method for the expression of a gene coding for a soluble proteinase K in yeast e.g. in Pichia pastoris with subsequent secretion into the culture medium. In addition a method for purifying the heterologously expressed and secreted proteinase K is described.

Abstract: The invention concerns a method for the recombinant production or expression of eukaryotic alkaline phosphatase mutants in yeast cells wherein the specifically introduced mutations result in a reduction of the specific AP activity by at least a factor 1:100. The invention also concerns a method for inserting corresponding nucleic acid sequences into a vector for expression in methylotrophic yeast strains and it concerns corresponding vectors and host strains.

Abstract: The invention concerns a process for the recombinant production and expression of eukaryotic alkaline phosphatase in yeast cells in which in particular a DNA coding for a eukaryotic highly active alkaline phosphatase having a specific activity above 3000 U/mg is used. The invention additionally concerns a process for inserting corresponding nucleic acid sequences into a vector for expression in methylotrophic yeast strains and it concerns appropriate vectors and host strains.

Abstract: The heterologous expression of the reverse transcriptase from the Avian Myeloblastosis Virus (AMV-RT) in prokaryotic cells and in particular Escherichia coli (E. coli) is described in the present invention. The invention also includes certain measures to simplify the purification of the heterodimeric AMV-RT.