Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 6 de 6
Filter
Add more filters










Database
Language
Publication year range
1.
FEMS Microbiol Lett ; 169(1): 29-36, 1998 Dec 01.
Article in English | MEDLINE | ID: mdl-9851032

ABSTRACT

The intracellular expression of the B subunit of cholera toxin (CTB) was first achieved in Lactobacillus paracasei LbTGS1.4 with an expression cassette including the P25 promoter of Streptococcus thermophilus combined with the translation initiation region from the strongly expressed L. pentosus D-lactate dehydrogenase gene (ldhD). Secretion of CTB was next attempted in L. paracasei LbTGS1.4 and L. plantarum NCIMB8826 with four different signal sequences from exported proteins of lactic acid bacteria (Lactococcus lactis Usp45 and PrtP, Enterococcus faecalis unknown protein and S. pyogenes M6 protein). Host-dependent secretion of CTB was clearly observed: whereas none of the secretion cassettes led to detectable CTB in the extracellular fraction of L. paracasei LbTGS1.4, secretion of CTB molecules was clearly achieved with three of the selected signal sequences in L. plantarum NCIMB8826.


Subject(s)
Cholera Toxin/biosynthesis , Lactobacillus , Base Sequence , Cholera Toxin/genetics , Cholera Toxin/metabolism , G(M1) Ganglioside/metabolism , Genetic Vectors , Molecular Sequence Data , Protein Binding , Recombinant Proteins/biosynthesis , Recombinant Proteins/metabolism , Species Specificity
2.
J Gen Virol ; 78 ( Pt 2): 359-66, 1997 Feb.
Article in English | MEDLINE | ID: mdl-9018058

ABSTRACT

Antigenic variation among eight bovine respiratory syncytial virus (BRSV) isolates was determined using monoclonal antibodies (MAbs) specific for the attachment (G) protein. Two major (and one intermediate) subgroups were identified, as well as one strain that did not fit any pattern. The subgroups could also be differentiated on the basis of the Mr of the F protein cleavage product, F2. The nucleotide sequence of the G gene of seven of the BRSV strains was determined and compared with published G gene sequences. Subgroups A and A/B were more closely related in protein sequence than subgroups A and B or subgroups A/B and B. These results could not be correlated with those obtained by the determination of the Mr of the F2 polypeptide. Multiple sequence alignments showed a high level of amino acid identity at the inter-subgroup level (85% identity between subgroup A and subgroup B strains), similar to the intra-subgroup human (H)RSV identity, suggesting that the BRSV isolates form a continuum rather than distinct subgroups. However, unusual variability was observed within the immunodominant domain (amino acids 174-188) in contrast with the situation in HRSV strains belonging to the same subgroup.


Subject(s)
Antigens, Viral/immunology , HN Protein , Respiratory Syncytial Virus, Bovine/immunology , Viral Proteins/immunology , Amino Acid Sequence , Animals , Antibodies, Monoclonal/immunology , Antibodies, Viral/immunology , Antigenic Variation , Antigens, Viral/genetics , Cattle , Cell Line , Chlorocebus aethiops , Cloning, Molecular , Molecular Sequence Data , Radioimmunoprecipitation Assay , Respiratory Syncytial Virus, Bovine/classification , Respiratory Syncytial Virus, Bovine/genetics , Sequence Homology, Amino Acid , Serotyping , Vero Cells , Viral Envelope Proteins , Viral Proteins/genetics
3.
Eur J Biochem ; 231(1): 214-9, 1995 Jul 01.
Article in English | MEDLINE | ID: mdl-7628473

ABSTRACT

The lack of crystal structure for tetrameric yeast alcohol dehydrogenases (ADHs) has precluded, until now, the identification of the residues involved in subunit contacts. In order to address this question, we have characterized the thermal stability and dissociation propensity of native ADH I and ADH II isozymes as well as of several chimeric (ADH I-ADH II) enzymes. Three groups of substitutions affecting the thermostability have been identified among the 24 substitutions observed between isozymes I and II. The first group contains a Cys277-->Ser substitution, located at the interface between subunits in a three-dimensional model of ADH I, based on the crystallographic structure of the dimeric horse liver ADH. In the second group, the Asp236-->Asn substitution is located in the same interaction zone on the model. The stabilizing effect of this substitution can result from the removal of a charge repulsion between subunits. It is shown that the effect of these two groups of substitutions correlates with changes in dissociation propensities. The third group contains the Met168-->Arg substitution that increases the thermal stability, probably by the formation of an additional salt bridge between subunits through the putative interface. These data suggest that at least part of the subunit contacts observed in horse liver ADH are located at homologous positions in yeast ADHs.


Subject(s)
Alcohol Dehydrogenase/metabolism , Saccharomyces cerevisiae/enzymology , Alcohol Dehydrogenase/chemistry , Alcohol Dehydrogenase/genetics , Animals , Crystallography, X-Ray , Enzyme Stability , Horses , Models, Molecular , Recombinant Fusion Proteins/chemistry , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/metabolism
4.
Gene ; 114(1): 19-24, 1992 May 01.
Article in English | MEDLINE | ID: mdl-1587481

ABSTRACT

The nucleotide sequences of two genes involved in sodium dodecyl sulfate (SDS) degradation, by Pseudomonas, have been determined. One of these, sdsA, codes for an alkyl sulfatase (58,957 Da) and has similarity (31.8% identity over a 201-amino acid stretch) to the N terminus of a predicted protein of unknown function from Mycobacterium tuberculosis. The other gene, sdsB, codes for a positive activator protein (33,600 Da) that has extensive similarity with the lysR family of helix-turn-helix DNA-binding activator proteins.


Subject(s)
Bacterial Proteins/genetics , Pseudomonas/enzymology , Sodium Dodecyl Sulfate/metabolism , Sulfatases/genetics , Trans-Activators/genetics , Transcription Factors/genetics , Amino Acid Sequence , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Base Sequence , Biodegradation, Environmental , Escherichia coli/genetics , Molecular Sequence Data , Protein Conformation , Pseudomonas/genetics , Sulfatases/chemistry , Sulfatases/metabolism , Trans-Activators/chemistry , Trans-Activators/metabolism , Transcription Factors/chemistry
6.
FEBS Lett ; 234(1): 61-4, 1988 Jul 04.
Article in English | MEDLINE | ID: mdl-2839366

ABSTRACT

The natural human H-chain ferritin was expressed in E. coli using a multi-copy expression vector containing the lambda pL promoter. A variant H-ferritin, having an altered N-terminus, was also produced. These proteins are overproduced (greater than 30% of the soluble protein), correctly assembled into its 24-subunit shell, and able to bind iron. The identity of the products was confirmed using an antibody specific for H-ferritin.


Subject(s)
Escherichia coli/genetics , Ferritins/genetics , Gene Expression Regulation , Bacteriophage lambda/genetics , Codon , DNA Restriction Enzymes , DNA, Recombinant , Electrophoresis, Polyacrylamide Gel , Genetic Engineering , Humans , Plasmids , Promoter Regions, Genetic
SELECTION OF CITATIONS
SEARCH DETAIL
...