43results about How to "No hemolytic activity" patented technology

The invention provides novel synthesis antibacterial peptides and application thereof. The novel synthesis antibacterial peptides are designed and synthesized on the basis of analyzing sequences and structures of natural antibacterial peptides, and the sequences of the novel synthesis antibacterial peptides comprise WYQ-a: ArgArgTrpTrpArg and WYQ-b: PheArgTrpTrpArg. The synthesis antibacterial peptides have the broad spectrum killing activity on gram-positive bacteria and gram-negative bacteria, have higher bactericidal activity than that of the natural antibacterial peptides, and do not have a toxic effect on animal and plant cells. The synthesis antibacterial peptides have broad antibacterial spectra and simple structures, are not needed to be modified and connected and are convenient to synthesize artificially. Experiments prove that: for G+bacteria (the gram-positive bacteria) and G-bacteria (the gram-negative bacteria), the novel synthesis antibacterial peptides have the obvious bacteriostatic and bactericidal activity and do not have hemolysis activity, so the synthesis antibacterial peptides have significant value in the development and application of antibacterial medicines.

The present invention relates to rana grahami antibiotic peptide and its application, and belongs to the field of biomedicine. Rana grahami antibiotic peptide is one kind of cyclic polypeptide separated from the secretion of amphibian rana grahami, and has molecular weight of 1705.3 dalton, isoelectric point of 9.39, and primary structure of polypeptide sequence Leu Lys Gly Cys Trp The Lys Ser Ile Pro Pro Lys Pro Cys Phe(LKGCWTKSIPPKPCF) with cysteines in the 4-th and 14-th forming intramolecular disulfide bond. Its preparation process includes collecting secretion of ether stimulated rana grahami, centrifuging to eliminate precipitate, freeze drying, chromatographic separation in filtering gel column and separating purification in reverse high pressure liquid chromatogram. The rana grahami antibiotic peptide has powerful effect of inhibiting bacteria, fungi and viruses and no hemolytic activity, and may be used in preparing medicine for treating pathogenic microbe infection diseases.

The invention discloses a citrus fruit fly antibacterial peptide, which is a polypeptide obtained from separation of a citrus fruit fly pupa, with a molecular weight of 2.3 daltons and an isoelectric point of 11.43, and the amino acid sequence of the antibacterial peptide is shown as SEQ ID NO: 1. The invention simultaneously discloses a method for preparing the citrus fruit fly antibacterial peptide, comprising the following steps that: the citrus fruit fly pupa is induced by adoption of a mixed bacteria solution; a crude extract is obtained through tissue homogenate; and the citrus fruit fly antibacterial peptide is obtained after purification through ion exchange chromatography, reversed fast protein liquid phase chromatography and reversed high pressure liquid phase chromatography of the crude extract. The citrus fruit fly antibacterial peptide provided by the invention has inhibition on gram positive bacteria, gram negative bacteria and fungi, has no hemolytic activity, can be taken as a raw material for developing human and poultry biotechnical products with pathogenic microorganism infection resistance, and can be taken as a disease-resistant gene to be used for breeding transgenic plants and transgenic animals by means of gene transformation and other biotechnologies.

The invention relates to bullfrog antibiotic peptide temporin-Lb, genes thereof and the application in the pharmacy, belonging to the biomedicine field. The bullfrog antibiotic peptide genes are obtained by filtering in a constructed bullfrog skin c DNA library; wherein, the molecular weight is 1691.11 dalton; the isoelectric point is 9.70; the primary structure of the complete sequence of the polypeptide is Leu Phe Arg His Val Val Lys Ile PheGIu Lys Tyr Leu-AMIDATION. The genes of the coding bullfrog antibiotic peptide are composed of 322 position nucleotide acid; wherein, the coding mature peptide is 142nd-180th position nucleotide acid. The synthetic bullfrog antibiotic peptide has obvious function of inhibiting the growth of the bacterial and fungus and can be taken as therapeutic drug for preparing pathogenic microorganism infection diseases to be applied.

The invention relates to a preparation method of an application of an artificial antimicrobial peptide MA-D4. According to the invention, an amino acid sequence of the artificial antimicrobial peptide MA-D4 is designed artificially, and a nucleotide sequence encoding the antimicrobial peptide is designed by using an escherichia coli preference codon; a target gene is synthesized by an overlap region amplification gene splicing method, and a prokaryotic expression vector is constructed and is transformed into the escherichia coli BL21 or Rosetta for inducing expression; an expressed product is subjected to digestion treatment by enterokinase and is subjected to nickel ion affinity chromatography purification, so as to obtain the artificial antimicrobial peptide MA-D4. The antimicrobial peptide has higher broad-spectrum antibacterial activity, can inhibit gram-positive bacteria and gram-negative bacteria, and meanwhile, excludes hemolytic activity. Therefore, as a novel antimicrobial drug, the antimicrobial peptide has excellent application prospect on the aspects of food preservation, disease treatment and the like, and has very high developing potential. The preparation method is high in expression efficiency, easy in separation and purification, low in production cost and good in stability, therefore, the preparation method can be used for mass production.

The invention provides a collagen secretion promotion ultrashort peptide and application thereof, and belongs to the technical field of biomedicine. The ultrashort peptide comprises at least one kind of materials from ultrashort peptides Magin-WH, Tinin-WH and Orin-G-OT, has the capability of promoting the collagen synthesis, and has the characteristics of very strong oxidization resistance, anti-aging performance, small molecular weight, simple structure, very low cell toxicity, no hemolytic activity, simple preparation method and the like. The ultrashort peptideis used for preparing medicine for treating injured skin restoration and regeneration, such as medicine for treating burnt injury, scald injury and skin ulceration, and can replace EGF to be used in the fields of anti-aging and anti-oxidization beatification skin care product new raw materials for skin restoration and skin collagen proliferation simulation and the like. The ultrashort peptide has small molecular weight and simple structure; the used chemical synthesis method has very low cost; the ultrashort peptide has the obvious beneficial characteristics through being compared with EFG with the sale price being nearly 2 million U.S dollars per gram.

The invention discloses a novel broad-spectrum antibacterial peptide SAMP1-A3 and a preparation method thereof. The amino acid sequence of the antibacterial peptide is NH2-RKKKVLLI-COOH. The preparation method of the invention adopts a solid-phase polypeptide synthesis means protected by amino acid nitrogen Fmoc. The method overcomes the defects of poor biological safety, easy hemolysis or toxicity to mammalian cells of common antibacterial peptides, and the novel antibacterial peptide has broad-spectrum inhibition effect on non-filamentous fungi and bacteria, does not have hemolysis and has no toxicity to normal mammalian cells. The polypeptide provides a novel leader for clinical antifungal drug research.

The invention discloses antibacterial peptide of bactrocera dorsalis hendel and derivatives and application of the antibacterial peptide. An amino acid sequence of antibacterial peptide is as shown in SEQ ID NO:1; the derivatives of antibacterial peptide are antibacterial active derivatives obtained through modification or antibacterial derivatives formed through substitution, deletion or addition of one or more amino acid residues; obtained antibacterial peptide BH-AMP003 has bioactivity and a wide antibacterial effect, so that antibacterial peptide BH-AMP003 can be applied to preparation of antibacterial products including feed additives, animal drugs, preservatives and medical products such as antibacterial drugs.

The invention discloses a degradable antibacterial peptide based on cellulose and a preparation method thereof. Comprising the following steps: step 1, adding cellulose into a sulfuric acid solution, carrying out acid treatment, and terminating the reaction with ethanol; centrifuging, washing and freeze-drying to obtain cellulose A; 2, dispersing cellulose A in deionized water to obtain a cellulose solution; the preparation method comprises the following steps: adjusting the pH value to 9, adding 1-(3-dimethylaminopropyl)-3-ethyl carbene imide and N-hydroxyl thiosuccinimide sodium salt, and stirring for 2 hours; adding excessive diamino compound, stirring for 10-12 hours, adding methoxy polyethylene glycol amine, and reacting for a period of time; carrying out ethanol precipitation, centrifugation, washing and freeze drying; the preparation method comprises the following steps: ultrasonically dispersing in water, adjusting the pH value to 3.5 by using 0.1 M hydrochloric acid, stirring for 2-4 hours, washing, dialyzing and freeze-drying to obtain the degradable antibacterial peptide.