45results about How to "Low hemolytic toxicity" patented technology

The invention relates to a recombinant bee venom polypeptide and its application. The amino acid sequence of the recombinant bee venom polypeptide is SEQ ID No.1. A recombinant bee venom fusion gene is constructed by connecting the UA8 short peptide with the melittin gene to form a recombinant bee venom fusion gene. The eukaryotic expression of the toxic polypeptide fusion gene carries U-melittin-pPICZα, which is transferred to Pichia pastoris to induce the expression of recombinant melittin and then expressed and purified. Compared with melittin, the present invention has stronger anti-tumor activity and smaller Hemolytic toxicity, used in the prevention and treatment of cervical related diseases and cervical cancer caused by HPV virus.

The invention relates to the technical field of antimicrobial peptides, in particular to a method for screening antimicrobial peptides and applications thereof. The invention discloses a method for screening antimicrobial peptides. The screening method can rapidly screen antimicrobial peptides with specific resistance for specific pathogenic bacteria. The polypeptides in the phage random peptide library selected in the screening method have small molecular weights, so that the antimicrobial peptides obtained by screening have small molecular weights, are easy to obtain by chemical synthesis, and reduce the production cost of the antimicrobial peptides. The antimicrobial peptide screened by the screening method has high bactericidal activity on pathogenic bacteria, and low cytotoxicity and hemolytic toxicity.

The invention provides an anti-enzymolysis α-helical antibacterial peptide bound by full carbon and hydrogen side chains, a preparation method and application thereof. The antimicrobial peptide sequence is shown in SEQ ID No.1. Preparation method: Based on the α-helical polypeptide folding principle, design a polypeptide sequence containing seven amino acid residues, select (S)-2-(4-pentenyl) alanine to be placed at the second position (b position ) and the 6th position (f position) to form a full carbon hydrogen binding side chain "book" structure, located in the "book" structure and its adjacent positions can hinder the hydrolysis of chymotrypsin. The sequence length of this antimicrobial peptide is only 7 amino acids, and the implantation of full carbon-hydrogen binding side chains has been invented to affect the biological activity of linear α-helical antibacterial peptides and the ability to resist protease hydrolysis. It is effective against a variety of Gram-negative bacteria and positive It has a strong inhibitory effect on erythrocytes, has extremely low hemolytic toxicity to red blood cells, and has a better effect on resistance to protease hydrolysis. It is expected to become an efficient substitute for traditional antibiotics.

The invention discloses a targeted drug delivery carrier based on PAMAM (polyamide amine). A structural formula is described in the specification. A preparation method of the targeted drug delivery carrier based on PAMAM comprises the step of connecting PAMAM having pH sensitivity with hydrophilic polyethylene glycol by virtue of a reduction-sensitive disulfide bond, so that a size-controlled reduction and pH sensitive nano drug delivery carrier is formed. The targeted drug delivery carrier based on PAMAM can obviously reduce cytotoxicity and hemolysis toxicity which are caused by high algebraic PAMAM and also can reduce intake of a reticuloendothelial system and prolong retention time in blood, so that the drug is effectively conveyed to tumour tissues;the disulfide bond in the targeted drug delivery carrier based on PAMAM breaks under high reducing environment and at low pH value in a tumour cell, and an inner core of PAMAM is opened, so that the drug can be rapidly and effectively released, and the aims of improving treatment effect of an anti-tumour drug and reducing toxic and side effects are achieved.

The invention discloses a positively charged cyclic antimicrobial peptide analogue, which is a derivative based on the skeleton of the natural antibacterial peptide gramicidin tyrosin A, which is obtained by introducing amino acids into the skeleton, and its structure is generally The formula is: cyclo‑( D FPF D FXXXZXZ), the present invention also discloses the synthesis method of the cyclic antimicrobial peptide analog and its application in the preparation of clinical antibacterial drugs. The invention has the advantages of simple design, low production cost, high metabolic stability, strong antibacterial activity, low hemolytic toxicity and difficult induction of bacterial drug resistance.