摘要:
The invention relates to a method for artificial in vivo evolution of proteins, said method making it possible to bring about the evolution of a protein X by complementation of a relative protein Y, X and Y both belonging to the same class of enzyme commission (EC) nomenclature or belonging to related classes. The mutants D133E and R104Q of desoxycytidine kinase (DCK) were obtained; both of said mutations result in acquisition of thymidine kinase activity by DCK.
摘要:
The invention concerns novel polypeptides and their fragments, isolated from Lactobacillus, having at least a N-deoxyribosyl transferase activity, the polynucleotides encoding said polypeptides, cloning and/or expression vectors including said polynucleotides, cells transformed by said vectors and specific antibodies directed against said polypeptides. The invention also concerns a method for enzymatic synthesis of deoxyribonucleosides.
摘要:
The present invention is directed to a method to diversify the chemical composition of proteins produced in vivo comprising the step of disabling, particularly by mutagenesis, the editing function of one of its aminoacyl tRNA synthetases. The present invention is also directed to nucleic acid sequences encoding such mutated aminoacyl tRNA synthetases having their editing site mutated and capable of mischarging its cognate tRNA with a noncanonical amino acid. Also described herein is an improved method for obtaining transformed cells capable of synthetizing in vivo proteins comprising at least a noncanonical amino acid and their use for the production of such proteins.
摘要:
The invention concerns a method for producing a cyclic L-amino acid of formula (I), characterised in that it consists in reacting a L-diamino acid of formula (II) or an enantiomeric mixture comprising such a L-diamino acid and a corresponding D-diamino acid in variable proportions, in the presence of an ornithine cyclodeaminase or a polypeptide homologous to the ornithine cyclodeaminase.
摘要:
The invention relates to a method for altering a protein X such as to modify the characteristics thereof by a) obtaining the mutants X* of the sequence coding for protein X, by means of aleatory mutagenesis, b) transformation of cells with a phenotype [P-] with vectors comprising the mutated nucleic acids obtained in step (a) which code for proteins X*, where P-signifies that said cells are auxotrophic for substance P, P begin the product of the action of X on the natural substrate thereof S, c) culturing said cells in a medium comprising a substrate S*, S* being an analogue of the natural substrate S of the protein X, d) selection of the cells [P-:: X*] which have survived step c) in which the proteins X* can biosynthesise the product P from the substrate S*. The invention further relates to mutated proteins X, nucleic acids, expression vectors, host cells comprising a vector, use of N-dideoxyribosyl transferases for the transfer of a dideoxyribose (ddR) from a dideoxyribonucleoside to another nucleoside, a method for production of compounds comprising a step using a mutated protein and a strain of E. coli.
摘要:
The present invention is directed to a method to diversify the chemical composition of proteins produced in vivo comprising the step of disabling, particularly by mutagenesis, the editing function of one of its aminoacyl tRNA synthetases. The present invention is also directed to nucleic acid sequences encoding such mutated aminoacyl tRNA synthetases having their editing site mutated and capable of mischarging its cognate tRNA with a noncanonical amino acid. Also described herein is an improved method for obtaining transformed cells capable of synthetizing in vivo proteins comprising at least a noncanonical amino acid and their use for the production of such proteins.
摘要:
The present invention relates to a method and a device for selecting accelerated proliferation of living cells in suspension. The culture apparatus (2) of the present invention enables cells to proliferate in suspension over unlimited periods of time. Natural selection results in the accumulation of genetic variants which are increasingly better adapted to the chosen culture conditions. The organisms used can be prokaryotic or eukaryotic. The organisms used can be naturally occurring organisms or genetically modified organisms. The culture apparatus of the present invention is also suitable for using continuous, periodical or conditional culture conditions. The physical and chemical characteristics of the culture media used can be chosen by the user. The requirement that a population of cells proliferates exclusively in suspension in continuous culture conditions is satisfied by the periodical transfer of the organism suspension from a first culture vessel into a second culture vessel. After the transfer, the first culture vessel is subjected to a sterilizing treatment and the sterilizing agent is optionally neutralized, so that the first culture vessel is ready for the culture to be transferred back from the second culture vessel. The second culture vessel is then sterilized and neutralized.
摘要:
The present invention relates to a method for generating a novel form of life comprising the steps consisting of: a) irreversible alteration of the genome of a microbial clone; b) cultivation of a vast population of microbial cells originating from the altered clone obtained in step a) during numerous generations under conditions allowing selection for a higher and stable proliferation rate; c) isolation of descendant clones within the cultivated population of step b) still bearing the alteration of step a).
摘要:
The present invention relates to a method for providing bacterial or yeast cells with the capacity to produce a protein, the amino acid sequence of which comprises at least one unconventional amino acid. The method involves (a) introducing at least one missense mutation in a target codon of a gene encoding a protein required for the growth of the bacterial or yeast cells, where the mutated protein synthesized from the mutated gene is not functional in the bacterial or yeast cells. The method also involves (b) selecting the bacterial or yeast cells obtained in (a) in a culture medium which (1) does not contain a nutrient compensating for the loss of functionality of the mutated protein and (2) contains an unconventional amino acid which restores the functionality of the protein required for growth of the bacterial or yeast cells, in which the unconventional amino acid is that encoded by the target codon. The method also involves culturing the bacterial or yeast cells obtained in (b) in a culture medium containing the amino acid encoded by the target codon.