Abstract: Polynucleotide sequences encoding enzymes that possess .alpha.2-3 neuraminidase activity are provided. Of particular interest are polynucleotide sequences encoding an enzyme having .alpha.2-3 neuraminidase activity and naturally produced by the bacteria Streptococcus pneumoniae. Recombinant DNA expression of enzymes possessing .alpha.2-3 specific neuraminidase activity is also described, including methods, recombinant host cells and a genetic construction. The invention also provides a purified enzyme having .alpha.2-3 neuraminidase activity from Streptococcus pneumoniae, wherein the enzyme is isolated from S. pneumoniea cultures. Another aspect of this invention is to provide methods of isolating genes encoding enzymes having neuraminidase activity, particularly .alpha.2-3 neuraminidase activity. The gene isolation methods of the invention comprise the step of labeling a hybridization probe derived from the neuraminidase coding portion of plasmid pND-1.

Abstract: A balanced constitutive inducible transcriptional control system is provided to facilitate the expression of polypeptides incompatible with recombinant host cells. Use of this system has, for the first time, made it possible to produce mature, unglycosylated human tissue plasminogen activator in prokaryotes which is water soluble and fully enzymatically active. In accordance with this invention, t-PA is produced by recombinant bacterial host cell culture in commercially significant amounts without in vitro renaturation and processing.

Abstract: A ubiquitin hydrolase is provided having a purity of at least 70% homogeneity based on the weight of the total protein in the composition. Also provided are DNA sequences encoding ubiquitin hydrolases, as well as expression systems for their recombinant production. Processes are provided for purification of a ubiquitin hydrolase from eukaryotes and for its use in recovering any desired polypeptide free from its fusion at its N-terminus with ubiquitin.

Abstract: A ubiquitin hydrolase is provided having a purity of at least 70% homogeneity based on the weight of the total protein in the composition. Also provided are DNA sequences encoding ubiquitin hydrolases, as well as expression systems for their recombinant production. Processes are provided for purification of a ubiquitin hydrolase from eukaryotes and for its use in recovering any desired polypeptide free from its fusion at its N-terminus with ubiquitin.

Abstract: In recombinant microorganisms which were rendered capable of converting 2,5-diketo-D-gluconic acid (2,5-DKG) to 2-keto-L-gulonic acid (2-KLG) by transfer of genetic material, the secondary metabolites and metabolic pathways leading to the metabolic diversion of 2-KLG and 2,5-DKG were determined, and the diversion of 2-KLG to L-iodonic acid (IA) or of 2,5-DKG to 5-keto-D-gluconate (5-KDH) was blocked.