Abstract: Synthesis of semi-synthetic monobactamic or .beta.-Lactamic antibiotics by using derivatives stabilized by various methods of penicillin G acylase from various microbial sources according to a thermodynamically controlled strategy in monophase water/cosolvent organic apolar systems, wherein the concentration of the cosolvent varies between 30% and 90%, the temperature between -10.degree. C. and 50.degree. C., the pH between 4.5 and 8.5, with concentrations of the antibiotic nucleus between 0.5 an 875 mM and acyl donor between 0.2 mM and 1M, with a relationship antibiotic ring/activated or free acyl donor, using a buffer between 0 and 1M. Application to the pharmaceutical industry.

Abstract: A peptide amidase isolated from the flavedo of citrus fruits, preferably oranges, which is capable of catalyzing the selective hydrolytic elimination of the free amino group on the C-terminal end of peptide amides but which does not cleave peptide bonds. The enzyme accepts D-amino acid residues in the C-terminal position, although the hydrolysis rate is much slower than with L-amino acid residues. The enzyme is weakly inhibited by serine protease inhibitors; has an optimal pH of 7.5.+-.1.5, an optimum temperature of 30.degree. C. at pH 7.5 and has an isoelectric point of pH 9.5. The peptide amidase is stable at pH 6.0-9.0. The molecular weight of the purified enzyme is 23,000 +/- 3000 daltons. A peptide amidase according to the present invention is particular useful in the production of peptides by continuous enzymatic reaction of N-protected amino acid or peptide alkyl esters with amides of amino acids.

Abstract: The present invention relates to an improved process for the preparation of 1-desoxynojirimycin. 1-Desoxynojirimycin can be reacted by alkylation on the nitrogen atom to give various saccharase inhibitors which are used therapeutically in the treatment of diabetes mellitus.

Abstract: A method is provided for increasing the solubility of an enzyme in an aqueous solution comprising providing a water-soluble anionic surfactant to the solution and further providing the solution with a pH above that which result in the formation of an enzyme/surfactant precipitate. The application is further directed to an aqueous solution containing an anionic surfactant and having an enzyme concentration contained therein which is higher than that possible in the absence of the surfactant.

Abstract: A process for the recovery and purification of L-asparaginase from Erwinia chrysanthemi is disclosed. The process involves the preparation of cellular acetone powder extract followed by either an ion exchange and affinity chromatography purification steps or by affinity chromatography alone. The column eluent is then dialyzed to produce substantially pure L-asparaginase.

Abstract: This invention relates to a process for producing immobilized L-asparaginase preparations. Its principal object is to produce immobilized L-asparaginase preparations which are excellent in antithrombogenicity and mechanical strength.The present invention is concerned with production of immobilized L-asparaginase preparations by pouring an aqueous solution containing 6% or more of a polyvinyl alcohol with a degree of hydrolysis of 97 mol. % or higher and a viscosity-average degree of polymerization of 1,800 or more an antileukemic asparaginase into a vessel or a mold of an appropriate shape, subjecting the solution to cooling, solidification and molding at a temperature of -15.degree. C. or lower and partially dehydrating the molded mass without thawing to a dehydration ratio of 5% by weight or more and, if desired, immersing the product in water.According to the invention, L-asparaginase can be embedded in a highly hydrous gel excellent in antithrombogenicity and mechanical strength by simple procedures.

Abstract: There is described a method of separating an asparaginase rich fraction from a thermophilic microoganism and then to divide this fraction into its D- and L-asparaginases. Substantially pure crystals of the D-asparaginase were obtained.

Abstract: A biochemically active matrix for use in a bio-artificial organ is disclosed. The biochemically active matrix has an enzyme covalently bonded to a matrix of organochemically cross-linked fibrin. The matrix may be suspended in a medium of agarose which irreversibly solidifies below 37.degree. C. The bio-artificial organ is useful for extracorporeal treatment of blood to remove excess substrate from the blood. .