Abstract:
The present invention relates to a method for improving the properties of a cellulolytic enzyme by amino acid substitution, deletion or insertion, the method comprising the steps of: a. constructing a multiple alignment of at least two amino acid sequences known to have three-dimensional structures similar to endoglucanase V (EGV) from Humicola insolens known from Protein Data Bank entry 4ENG; b. constructing a homology-built three-dimensional structure of the cellulolytic enzyme based on the structure of the EGV; c. identifying amino acid residue positions present in a distance from the substrate binding cleft of not more than 5 Å; d. identifying surface-exposed amino acid residues of the enzyme; e. identifying all charged or potentially charged amino acid residue positions of the enzyme; f. choosing one or more positions wherein the amino acid residue is to be substituted, deleted or where an insertion is to be provided; and g. carrying out the substitution, deletion or insertion by using conventional protein engineering techniques. Also described are cellulase variants obtained by this method.
Abstract:
The present invention relates to a method for improving the properties of a cellulolytic enzyme by amino acid substitution, deletion or insertion, the method comprising the steps of: a. constructing a multiple alignment of at least two amino acid sequences known to have three-dimensional structures similar to endoglucanase V (EGV) from Humicola insolens known from Protein Data Bank entry 4ENG; b. constructing a homology-built three-dimensional structure of the cellulolytic enzyme based on the structure of the EGV; c. identifying amino acid residue positions present in a distance from the substrate binding cleft of not more than 5 Å; d. identifying surface-exposed amino acid residues of the enzyme; e. identifying all charged or potentially charged amino acid residue positions of the enzyme; f. choosing one or more positions wherein the amino acid residue is to be substituted, deleted or where an insertion is to be provided; and g. carrying out the substitution, deletion or insertion by using conventional protein engineering techniques. Also described are cellulase variants obtained by this method.
Abstract:
A process for making DNA libraries in filamentous fungal cells using a novel cloned gene involved in the mismatch repair system of filamentous fungal cells.
Abstract:
A maltogenic amylase enzyme with improved thermostability, which can be produced by cultivating Bacillus strain NCIB 11837 belonging to the Bacillus stearothermophilus complex, is made by cultivation of a host microorganism transformed with the gene coding for the maltogenic amylase enzyme.
Abstract:
A DNA construct comprising the following sequence: 5'-P-SP-(LP).sub.n -PS-HP-3' wherein P is a promoter sequence, SP is a DNA sequence encoding the yeast aspartic protease 3 (YAP3) signal peptide, LP is a DNA sequence encoding a leader peptide, n is 0 or 1, PS is a DNA sequence encoding a peptide defining a yeast processing site, and HP is a DNA sequence encoding a polypeptide which is heterologous to a selected host organism. The YAP3 signal peptide provides efficient secretion of heterologous proteins in yeast.
Abstract:
The present invention relates to a method for improving the properties of a cellulolytic enzyme by amino acid substitution, deletion or insertion, the method comprising the steps of: a. constructing a multiple alignment of at least two amino acid sequences known to have three-dimensional structures similar to endoglucanase V (EGV) from Humicola insolens known from Protein Data Bank entry 4ENG; b. constructing a homology-built three-dimensional structure of the cellulolytic enzyme based on the structure of the EGV; c. identifying amino acid residue positions present in a distance from the substrate binding cleft of not more than 5 Å; d. identifying surface-exposed amino acid residues of the enzyme; e. identifying all charged or potentially charged amino acid residue positions of the enzyme; f. choosing one or more positions wherein the amino acid residue is to be substituted, deleted or where an insertion is to be provided; and g. carrying out the substitution, deletion or insertion by using conventional protein engineering techniques. Also described are cellulase variants obtained by this method.
Abstract:
The present invention relates to a method for improving the properties of a cellulolytic enzyme by amino acid substitution, deletion or insertion, the method comprising the steps of: a. constructing a multiple alignment of at least two amino acid sequences known to have three-dimensional structures similar to endoglucanase V (EGV) from Humicola insolens known from Protein Data Bank entry 4ENG; b. constructing a homology-built three-dimensional structure of the cellulolytic enzyme based on the structure of the EGV; c. identifying amino acid residue positions present in a distance from the substrate binding cleft of not more than 5 Å; d. identifying surface-exposed amino acid residues of the enzyme; e. identifying all charged or potentially charged amino acid residue positions of the enzyme; f. choosing one or more positions wherein the amino acid residue is to be substituted, deleted or where an insertion is to be provided; and g. carrying out the substitution, deletion or insertion by using conventional protein engineering techniques. Also described are cellulase variants obtained by this method.
Abstract:
A fuel cell stack comprising alternating solid oxide fuel cell plates (10) and gas separator plates (30) stacked face to face with one or more seal assemblies (34, 36, 37, 38, 40) provided between opposed generally planar surfaces (33, 54) of each adjacent pair of plates. Each seal assembly comprises a pair of rigid ribs (36, 37) projecting from one surface (33) with a valley (38) therebetween and a third rigid rib (34) projecting from the other surface (54) and nested between the pair of ribs. Opposed contact surfaces (54, 60, 61) cooperate to define the maximum insertion of the third rib (34) into the valley (38). The third rib (34) has a profile that leaves a void between the valley (38) and the third rib (34) at said maximum insertion. A glass sealant (40) in said void contacts the surface of the valley (38) and the third rib (34). In a preferred embodiment each rib (34, 36, 37) tapers away from the respective surface (33, 54) towards a distal surface (51, 61) of the rib.
Abstract:
The present invention relates to cellulase variants, i.e., endo-beta-1,4-glucanase variants, derived from a parental cellulase, i.e., endo-beta-1,4-glucanase, by substitution, insertion and/or deletion, which variant has a catalytic core domain, in which the variant at position 5 holds an alanine residue (A), a serine residue (S), or a threonine residue (T); at position 8 holds a phenylalanine residue (F), or a tyrosine residue (Y); at position 9 holds a phenylalanine residue (F), a tryptophan residue (W), or a tyrosine residue (Y); at position 10 holds an aspartic acid residue (D); and at position 121 holds an aspartic acid residue (D).
Abstract:
Synthetic leaders for effective secretion of proteins in yeast are provided. Also provided are replicable yeast vectors containing a DNA-sequence encoding the synthetic leader positioned upstream to a DNA-sequence encoding the desired product and operably connected with promoter and signal sequences. There are also provided yeast strains transformed with such vectors and a method for producing proteins by means of the transformed yeast strains.