Abstract: A method for selecting amino acid residues is disclosed which upon replacement will give rise to an enzyme with an altered pH optimum. The method is specific for metalloenzymes which are inactivated at low pH due to the dissociation of the metal ions. The method is based on altering the pK.sub.a of the metal coordinating ligands or altering the K.sub.ass for the metal binding. New glucose isomerases with an altered pH optimum are provided according to this method. These altered properties enable starch degradation to be performed at lower pH values.

Abstract: The invention pertains to a method for the production of a biologically active modified protein derived from a starting protein having essentially the same kind of biological activity with an attendant modulation effect on, particularly increase of, the stability as compared with that of the starting protein. The method comprises substituting an arginine residue for a lysine residue of the starting protein at a site that can sterically accommodate the substitution, without substantially altering the biological activity of the starting protein, said site being preferably of low solvent accessibility, at interfaces between domains or sub-units of the starting protein.

Abstract: The subject invention describes the cloning and overexpression of leader peptidase genes. A method for isolating a leader peptidase gene is disclosed. Overexpression of the signal peptidase in a suitable host species leads to an enhanced rate of protein processing.

Abstract: The invention provides a gene encoding penicillin G acylase, the enzyme encoded by said gene and a method for the production of said enzyme by incorporating said gene in a host and bringing the same to expression. The gene is preferably obtained from a strain of the microorganism Alcaligenes faecalis.

Abstract: A process for the preparation of a pharmaceutically active compound in a stereospecific form of the formula ##STR1## or a pharmaceutically acceptable salt or ester thereof, like an alkali metal salt or an alkaline earth metal salt or a pivaloyl ester, wherein R.sub.1 represents an optionally substituted aryl group such as a phenyl or naphthyl group optionally included in a heterocyclic ring system, which is optionally substituted, or represents a heteroaromatic ring system containing in addition to carbon atoms one or more atoms selected from nitrogen, sulphur and oxygen, this ring system being optionally substituted, which comprises subjecting a compound of the formula ##STR2## wherein R.sub.

Abstract: A process for the preparation of a pharmaceutically active compound in a stereospecific form of the formula ##STR1## or a pharmaceutically acceptable salt or ester thereof, like an alkali metal salt or an alkaline earth metal salt or a pivaloyl ester, wherein R.sub.1 represents an optionally substituted aryl group such as a phenyl or naphthyl group optionally included in a heterocyclic ring system, which is optionally substituted, or represents a heteroaromatic ring system containing in addition to carbon atoms one or more atoms selected from nitrogen, sulphur and oxygen, this ring system being optionally substituted, which comprises subjecting a compound of the formula ##STR2## wherein R.sub.