摘要:
New mutant .beta.-lactam acylases are provided exhibiting altered substrate specificities. These .beta.-lactam acylases are obtained by expression of a gene encoding said .beta.-lactam acylase and having an amino acid sequence which differs at least in one amino acid from the wild-type .beta.-lactam acylase.
摘要:
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.
摘要:
Heterologous protein secretion from Gram-positive bacteria, in particular from Bacilli has, with few exceptions, met with little success. Incompatibility of the heterologous proteins with the protein secretion machinery of the host is the main cause of this effect. This limiting factor for the production of heterologous proteins in commercially significant concentrations from Bacillus subtilis is removed by overexpressing the Bacillus subtilis protein FtsY or FtsY protein in combination with overexpression of other members of the bacterial signal recognition particle. Said gene(s) is(are) overexpressed in Bacillus host cells expressing a heterologous protein which then shows an increased amount of the heterologous protein secreted in the surrounding medium.
摘要:
A new expression system is provided which comprises component(s) of a lipase regulation cascade. the lipase regulation cascade as disclosed herein includes a kinase, a DNA binding regulator, a polymerase, a promoter, an upstream activating sequence, and secretion factors. Plasmids and transformed cells are also provided as well as methods of transforming host cells using the plasmids. Further, there is provided a kinase that can regulate the expression of a protein, a DNA binding regulator that can regulate the expression of a protein, a Pseudomonas alcaligenes polymerase, a Pseudomonas alcaligenes sigma 54 promoter, a Pseudomonas alcaligenes upstream activating sequence, the Pseudomonas alcaligenes secretion factors XcpP, XcpQ, XcpR, XcpS, XcpT, XcpU, XcpV, XcpW, XcpX, XcpY, XcpZ and the xcp regulators OrfV, OrfX.
摘要:
New mutant .beta.-lactam Penicillin G acylases are provided, exhibiting altered substrate specificities. These Penicillin G acylases are obtained by expression of a gene encoding for said Penicillin G acylase and having an amino acid sequence which differs at least in one amino acid from the wild-type Penicillin G acylase.
摘要:
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.
摘要:
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.
摘要:
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.1 is an ester residue and preferably an alkyl group optionally substituted, to the action of a micro-organism having the ability for stereoselective hydrolysis of compound (II) into compound (I), having at least 80% by weight the S-configuration, and if desired converting compound (I) into the pharmaceutically acceptable salt or ester thereof.
摘要:
The present invention relates to novel methods for the design of proteins, in particular, cytokines. These methods allow the stabilisation of such cytokines, as well as modification of their selectivity/specificity for their cognate receptors. The invention also relates to various modified proteins that have been designed by the methods of the invention.
摘要:
Heterologous protein secretion from Gram-positive bacteria, in particular from Bacilli has, with few exceptions, met with little success. Incompatibility of the heterologous proteins with the protein secretion machinery of the host is the main cause of this effect. This limiting factor for the production of heterologous proteins in commercially significant concentrations from Bacillus subtilis is removed by overexpressing the Bacillus subtilis protein FtsY or FtsY protein in combination with overexpression of other members of the bacterial signal recognition particle. Said gene(s) is(are) overexpressed in Bacillus host cells expressing a heterologous protein which then shows an increased amount of the heterologous protein secreted in the surrounding medium.