9 results about "DNA shuffling" patented technology

The invention belongs to the technical field of gene engineering and enzyme engineering, and particularly discloses a neutral protease mutant and application thereof. A DNA shuffling technology is used for carrying out directed evolution on neutral metalloproteinase empr obtained by amplifying a bacillus LCB14 genome, a high-activity neutral protease mutant gene is obtained after screening, the mutant gene is used for constructing a recombinant vector, the recombinant vector is successfully expressed in pichia pastoris, and a recombinant strain with improved enzyme activity is obtained. The obtained neutral protease mutant emps can be applied to the fields of textile leather industry, food industry, feed industry and medicine, has excellent depilation performance when being applied to a depilation process of a leather making process, obviously improves the depilation efficiency, and has a very good application prospect in the leather industry.

The invention discloses a DNA shuffling method based on flanking sequence segmented amplification and application of the DNA shuffling method in screening herbicide-resistant hybrid enzymes, on the basis of a single-stranded DNA shuffling technology, the success rate of single-stranded preparation is increased by introducing flanking sequences and segmented amplification recombinant products into single-stranded amplification primers, and the yield of herbicide-resistant hybrid enzymes is increased. Meanwhile, the proportion of nonsense mutation in the mutation library is reduced. The method is expected to provide a new method for establishing a protein qualitative evolution mutation library. The method is used for shuffling the rice and corn hppd genes and screening to obtain the hybrid enzyme of which the resistance is stronger than that of parent rice and corn HPPD under the treatment of 300 mu M mesotrione.

This invention relates to the field of biomedicine and specifically to a porcine interferon-like recombinant protein and its applications. By constructing and screening a PoIFN-α DNA shuffling bacterial library, a highly active recombinant protein Porferon was obtained. Porferon exhibits potent anti-infective activity against a broad range of porcine pathogens, including viruses, bacteria, and parasites. Its biological activity is significantly superior to that of natural porcine interferon. As such, Porferon can be used in the development of therapeutics for the prevention or treatment of infectious diseases in pigs, offering a novel and effective solution for clinical applications in veterinary medicine.

The invention belongs to the technical field of gene engineering, and particularly relates to a directed evolution method and application. The method comprises the following steps: dividing a full-length DNA (deoxyribonucleic acid) sequence of a target into at least two regions, respectively carrying out error-prone PCR (polymerase chain reaction), carrying out full-length sequence assembly on a mutation region and an unmutated region, screening a target mutant by adopting high throughput, carrying out regional amplification on the obtained target mutant to obtain a beneficial mutation region, the beneficial mutation region is amplified for full-length sequence assembly, and finally, a target mutant is obtained through high-throughput screening. According to the method disclosed by the invention, by carrying out segmented error-prone PCR and directional DNA shuffling on a full-length DNA sequence, limited digestion of DNase I or other restriction enzymes is not needed, so that reverse mutation of a recombinant DNA region can be prevented from occurring from the source, accumulation and average distribution of beneficial mutations are ensured, the screening difficulty and strength of beneficial mutants are reduced, and the screening efficiency of the beneficial mutants is improved. The method can be widely applied to molecular modification of proteins, enzymes or DNA sequences.

The application provides a SARS-related coronavirus universal antigen and a preparation method and application thereof, and belongs to the technical field of immunity. The candidate antigen prepared by the application has higher S309 antibody and detection serum binding activity, the titer of serum obtained by immunizing mice with the candidate antigen has higher cross-binding activity to VOCs than that of template antigen immunized serum; meanwhile, the candidate antigen immunized serum has the ability to block the combination of VOCs and ACE2. Therefore, the candidate antigen prepared by the application can become a potential universal antigen or combination for inducing cross-neutralization activity for preventing SARS-related coronavirus infection. The strategy of preparing the candidate antigen with cross-neutralization immunogenicity based on DNA Shuffling and membrane mutation antigen screening technology is expected to be applied to universal vaccine research and development. The candidate universal antigen prepared by the application has the potential to be developed into a SARS-related coronavirus universal vaccine.

The invention belongs to the technical field of biology, and discloses an artificially modified cephalosporin C acylase mutant and application thereof. The mutant is obtained by carrying out molecular evolution on wild-type enzyme through a DNA shuffling technology, the amino acid sequence of the mutant is shown as SEQ ID NO: 1, and compared with the wild-type enzyme, the mutant has remarkably improved catalytic activity and can efficiently catalyze cephalosporin C deamidation to generate 7-aminocephalosporanic acid. The invention also discloses a nucleic acid molecule for coding the acylase, a recombinant vector and a recombinant host cell containing the nucleic acid molecule, and application of the acylase or the recombinant host in production of 7-ACA by using cephalosporin C as a substrate.

The invention belongs to the technical field of biological medicine, and particularly relates to porcine interferon-like recombinant protein and application thereof. The porcine interferon-like recombinant protein Porferon with high activity is obtained by constructing a porcine interferon alpha (PoIFN-alpha) DNA (deoxyribonucleic acid) Shuffling bacterial library and screening the bacterial library, the recombinant protein has a good anti-infection effect on diseases caused by porcine viruses, bacteria, parasites and the like, and the activity of the recombinant protein is remarkably higher than that of porcine natural interferon. Therefore, the porcine interferon-like recombinant protein Porferon can be used for preparing medicines for preventing or treating diseases related to porcine virus, bacterium or parasite infection, and a novel prevention or / and treatment scheme is provided for clinic.

This invention discloses a high-performance laccase mutant constructed based on multi-source gene recombination and its applications. Using BspLac from Bacillus sp. SL-1 and BLTCLac from Bacillus licheniformis TCCC111219 as templates, a mutant library DS was constructed using DNA shuffling technology. Two high-performance laccase mutants, DS2 and DS5, were obtained through screening. Dynamic enzyme production analysis showed that the laccase activity of DS2 peaked at 1922 U / L after 24 hours, equivalent to twice that of the original strain; the laccase activity of DS5 peaked at 1337 U / L after 24 hours, equivalent to 1.4 times that of the original strain. Simultaneously, experimental verification showed that DS2 and DS5 achieved degradation rates of 83% and 89% for malachite green, respectively. This laccase mutant significantly improved the detoxification efficiency of synthetic dyes and possesses good potential for industrial application.

The invention provides an SARS (severe acute respiratory syndrome) related coronavirus universal antigen as well as a preparation method and application thereof, and belongs to the technical field of immunity. The prepared candidate antigen has high binding activity to an S309 antibody and detected serum, and the cross binding activity of the titer of serum obtained by immunizing a mouse with the candidate antigen to VOCs is higher than that of template antigen immunized serum; meanwhile, the candidate antigen immune serum has the capability of blocking the combination of VOCs and ACE2. Therefore, the candidate antigen prepared by the invention can become a potential universal antigen or combination for preventing SARS-related coronavirus infection and inducing cross neutralization activity. The strategy of preparing candidate antigens with cross-neutralization immunogenicity based on DNA Shuffling and a membrane mutation antigen screening technology is expected to be applied to research and development of universal vaccines. The candidate universal antigen prepared by the invention has the potential of being developed into an SARS-related coronavirus universal vaccine.