7 results about "Gene engineering" patented technology

The invention discloses a 1,3-1,4-beta-glucanase mutant, and belongs to the fields of gene engineering and enzyme engineering. Lysine in the 20th position, 117th position and 165th position of 1,3-1,4-beta-glucanase from Bacillus terquilensis mutates through an overlapping extension PCR method to form serine in order to obtain single mutants K20S, K117S and K165S respectively. The above three mutation sites are integrally mutated to obtain a K20S/K117S/K165S triple mutant enzyme. Four mutant enzymes have higher catalysis activity and better thermal stability. Compared with wild enzymes, the above mutant enzymes are in favor of realizing the industrial application.

The invention relates to the fields of gene engineering and molecular biology and provides a method for capturing a nucleic acid fragment. The method comprises the following steps: A, preparing a capture probe by using biotin labeled amplimers or joint elements with nucleic acid molecules containing a to-be-captured nucleic acid fragment as a raw material; and B, hybridizing the capture probe with a to-be-captured nucleic acid fragment library and capturing the to-be-captured nucleic acid fragment by using a solid phase carrier containing a streptavidin or avidin mark. The method for capturing the nucleic acid fragment in the invention can avoid occurrence of poor capture effects caused by poor homogeneity of the capture probe and enables cost for capturing of nucleic acid fragments to be reduced.

The invention relates to the field of biomedicines, in particular to a method for inducing differentiation of stem cells into islet-like cells in vitro and use of islet-like cells. The invention aims to provide a method for obtaining a large amount of islet-like cells in vitro and the use of the islet-like cells differentiated under induction as seed cells in transplantation of islet cells and preparation of microencapsulated stem cell preparation and as an in-vitro pharmacokinetic model in cell medicine screening. For realizing the aim, the invention adopts a technical scheme that: 1) constructing an NRSF interfering carrier; 2) separating, culturing and amplifying stem cells; 3) inducing stem cells to differentiate into islet-like cells by two stages; and 4) identifying islet-like cells. The construction of the method has a very bright application prospect in regenerative medicine taking gene engineering, cell engineering, tissue engineering and the like as a basis and is expected to create huge social and economic benefit.

The invention discloses a recombinant saccharomyces cerevisiae strain for secretory expression of hyaluronidase of capitella teleta, and belongs to the technical field of gene engineering. A hyaluronidase gene from capitella teleta is in cloned connection to a saccharomyces cerevisiae integration expression vector pRS305 by adopting a recombinant DNA technology; plasmid pGAP(m)-sp23-6xGln-HAase isobtained by means of replacing a promoter, adding a signal peptide and adding amino acid oligopeptide and the like to the N end of the gene; the saccharomyces cerevisiae host S.cerevisiae CEN.PK2-1Cis transformed to construct the recombinant strain for high yielding hyaluronidase which is named as S.cerevisiae CEN.PK2-1C-pGAP(m)-sp23-6xGln-HAase. In a 3L tank, the vitality of hyaluronidase for extracellularly expressing the recombinant S.cerevisiae strain can be 1.26*10<6>U/mL, and is increased by 5.1 times intracellular vitality, which is 2.05*10<5>U/mL, of recombinant strain S.cerevisiae pRS305-HAase. The hyaluronidase obtained by fermenting the saccharomyces cerevisiae serving as host has high selectivity and high vitality for hyaluronic acid, and has an important application prospect.

The invention relates to the technical field of gene engineering, in particular to a chimera for specifically degrading tau protein, an encoding gene of the chimera and application of the chimera andthe encoding gene. The chimera comprises a tau protein binding sequence, a connecting sequence and a ubiquitin ligase recruiting sequence, wherein the tau protein binding sequence is connected with the ubiquitin ligase recruiting sequence through the connecting sequence. The chimeric capable of specifically degrading the tau protein can enhance the degradation of the tau protein in cells, so thatthe content of the tau protein is reduced; a chimera in the AAV-PROTAC can be normally expressed in a hippocampal region of a C57BL/6 mouse, and human tau protein is effectively degraded; AAV-PROTAC is injected into the hippocampal region of a 3xTg AD model mouse, so that the human tau protein can be effectively degraded. Therefore, the chimera capable of specifically degrading the tau protein canplay a role in preventing and treating a series of tau diseases including Alzheimer's disease.

The invention relates to the technical field of gene engineering, in particular to a proline protease mutant and application thereof. The proline protein mutant screened by a directed evolution technology has an optimal reaction pH value of 4.0, an optimal reaction temperature of 55 DEG C, can keep 80% or above of the enzyme activity in the temperature range of 45 to 60 DEG C, and has remarkably-higher heat resistance than a wild type. The mutant can be widely applied to beer production, and can remarkably lower the turbidity of beer.