Abstract: Bi-cistronic plasmids used for the expression of formate dehydrogenase (FDH) and modified phenylalanine dehydrogenase (PDHmod) are provided.

Abstract: The present invention relates to a process for preparing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane comprising contacting a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648 with (3S)-1-halo-2-oxo-3-(protected)amino-4-substituted butane substrate. The present invention also relates to a process comprising mixing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane with at least one base in the presence of at least one solvent to produce a reaction mixture containing (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane. The present invention further relates to a process comprising crystallizing the (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane out of the reaction mixture by concurrently adding water and the reaction mixture together. The present invention is also directed to a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648.

Abstract: Bi-cistronic plasmids used for the expression of formate dehydrogenase (FDH) and modified phenylalanine dehydrogenase (PDHmod) are provided.

Abstract: The present invention relates to a process for preparing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane comprising contacting a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648 with (3S)-1-halo-2-oxo-3-(protected)amino-4-substituted butane substrate. The present invention also relates to a process comprising mixing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane with at least one base in the presence of at least one solvent to produce a reaction mixture containing (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane. The present invention further relates to a process comprising crystallizing the (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane out of the reaction mixture by concurrently adding water and the reaction mixture together. The present invention is also directed to a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648.

Abstract: The present invention relates to a process for preparing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane comprising contacting a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648 with (3S)-1-halo-2-oxo-3-(protected)amino-4-substituted butane substrate. The present invention also relates to a process comprising mixing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane with at least one base in the presence of at least one solvent to produce a reaction mixture containing (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane. The present invention further relates to a process comprising crystallizing the (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane out of the reaction mixture by concurrently adding water and the reaction mixture together. The present invention is also directed to a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648.

Abstract: The present invention relates to a process for preparing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane comprising contacting a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648 with (3S)-1-halo-2-oxo-3-(protected)amino-4-substituted butane substrate. The present invention also relates to a process comprising mixing (2R,3S)-1-halo-2-hydroxy-3-(protected)amino-4-substituted butane with at least one base in the presence of at least one solvent to produce a reaction mixture containing (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane. The present invention further relates to a process comprising crystallizing the (2R,3S)-1,2-epoxy-3-(protected)amino-4-substituted butane out of the reaction mixture by concurrently adding water and the reaction mixture together. The present invention is also directed to a mutagenized Rhodococcus erythropolis having ATCC deposit no. PTA-6648.

Abstract: A method of making didanosine (ddI) including the steps of: (a) obtaining an enzyme expressing ddA deaminase activity; (b) immobilizing the enzyme onto an insoluble support; (c) contacting the enzyme with a dideoxyadenosine (ddA) solution of at least about 4% weight volume ddA in water for a time and under conditions to produce a ddI solution; and (d) isolating the ddI from the ddI solution. Optionally, the ddI mother liquor is reused in subsequent runs to improve yield.

Abstract: A D-amino acid oxidase promoter isolated from T. variabilis has been incorporated into S. cerevisiae expression vectors to increase the expression of heterologous genes. The heterologous promoter has been placed upstream of selective markers, auxotrophic nutritional and/or dominant selectable markers. Because the promoter is from another yeast specie, it is weakly recognized by and S. cerevisiae. To compensate for the weak transcripts of selectable marker genes transcribed from the weak heterologous promoter, the plasmid containing the gene of the interest is amplified leading to a higher expression of protein of interest.