35 results about "Plectasin" patented technology

A method of preparing yeast strains (especially Pichia pastoris) for multi-copy expression of recombinant plectasin. The method comprises: optimizing the gene sequence of plectasin according to codon bias of Picha pastoris; fusing the optimized gene to the a-factor signal peptide C-terminal of the expression vector pPICZ a A to construct a single-copy expression vector containing a plectasin expression cassette composed of an initial signal component alcohol:oxygen dehydrogenase strong promoter, an a-factor signal peptide gene and a plectasin gene fused to the C-terminal thereof, and a termination signal component; using the mutually-complementing characteristics of the sticky ends of restriction endonucleases BglII and BamHI to obtain, by repeated digestion, ligation and transformation, recombinant plasmid with a tandem expression cassette containing different copies of the plectasin gene; and transforming the recombinant plasmid into Pichia pastoris. The yeast strains can achieve highly-efficient secretory expression of plectasin under methanol induction.

The invention discloses an application of plectasin in inhibiting streptococcus agalactiae. The plectasin is found to be good at inhibiting the streptococcus agalactiae through bacteriostasis experiments; the plectasin is further prepared into corresponding agentia, such as plectasin gel and plectasin emulsion, the agentia achieve good curative effects for mastitis, wherein the antibacterial anti-inflammatory effect of the gel is better, the action time lasts longer, the moisturizing effect is better, action sites can be effectively isolated from making contact with air, and a wound is prevented from infection and inflammation. The plectasin can be used for preparing bacteriostat of the streptococcus agalactiae and further used for curing the mastitis, and especially for the mastitis caused by the streptococcus agalactiae which is difficult to cure at present, and a good curative effect is achieved.

The present invention relates to isolated variants of an antimicrobial peptide plectasin, comprising a substitution at positions 9, 13 and 32, wherein the variant has antimicrobial activity and methods for treatment of treatment of diseases mediated by Mycobacterium tuberculosis and gram-positive bacteria.

The invention discloses a fusion expression plectasin, a preparation method and application thereof. The amino acid sequence of the recombinant plectasin is SEQ ID NO:1; and a nucleotide sequence designed according to an escherichia coli preferred codon is SEQ ID NO:2. According to the invention, a prokaryotic expression vector is utilized to construct the escherichia coli BL21 (DE3) host strain capable of expressing plectasin-thioredoxin fusion protein. The strain is subjected to multiplication culture, isopropyl-beta-D-isopropylthiogalactoside induction expression is carried out, centrifugation is performed to harvest thallus, the thallus is cracked, then centrifugation is conducted to acquire the supernatant, and affinity chromatography purification is carried out to obtain plectasin fused protein, the growth of gram positive staphylococcus aureus, streptococcus pneumoniae and the like can be significantly inhibited without removing thioredoxin by enzyme digestion. According to the invention, plectasin fused protein has obvious bacteriostatic effect without removing fusion protein by enzyme digestion, and the production cost is greatly reduced.

The invention discloses recombinant bacteria for expressing plectasin and an application thereof. The classification name of the recombinant bacteria is lactococcus lactis NZ9700-pGMN3, the preservation serial number of the recombinant bacteria is CCTCC NO: M2014611, the recombinant bacteria can achieve upper-high expression of plectasin protein, the expression quantity of the recombinant bacteria far exceeds that of other anode recombinant bacteria, and the recombinant bacteria can be directly used for preparing anti-bacteria medicament, have no hidden safety risks and hardly have any side effects. The recombinant bacteria have the functions of inhibition of methicillin-resistant staphylococcus aureus, streptococcus agalactiae, streptococcus pyogenes, enterococcus faecalis and the like. Bacterial strains of the recombinant bacteria can achieve efficient and continuous expression under self-induction, the recombinant bacteria can express and secrete fusion protein containing plectasin in the fermentation process, the total yield of protein is more than 1.41g / L, plectasin accounts for more than 70%, and the recombinant bacteria have the potential of treating mammitis and infectious diseases of a genital tract.