CN-119954924-B - Antiviral polypeptide modified based on Cecropin D and application thereof in inhibiting porcine reproductive and respiratory syndrome virus infection

Abstract

The invention discloses an antiviral polypeptide based on Cecropin D (CD) transformation and application thereof in inhibiting porcine reproductive and respiratory syndrome virus (Porcine Reproductive and Respiratory Syndrome virus, PRRSV) infection. The amino acid sequence of the antiviral polypeptide is shown as SEQ ID NO.2, SEQ ID NO.3 or SEQ ID NO. 4. The invention is based on the balance of hydrophilicity and hydrophobicity, and three derivatives of CD-2, CD-3 and CD-4 are designed and synthesized by modifying the parent peptide CD. Compared with other researches on known antiviral polypeptides, the polypeptide disclosed by the invention has obvious anti-PRRSV activity at a lower concentration (100 mug/mL), which shows that the polypeptide designed and synthesized by the invention has higher safety and application potential in anti-PRRSV drug development, and the invention provides a novel technical means for inhibiting PRRSV infection.

Inventors

• SUN SHIQI
• YIN SHUANGHUI
• MU SUYU
• DING YAOZHONG
• ZHOU JINGJING
• GUO HUICHEN
• Zang Haoyue
• ZHANG YUN
• TENG ZHIDONG
• BAI MANYUAN
• DONG HU
• WU JINEN

Assignees

• 中国农业科学院兰州兽医研究所(中国动物卫生与流行病学中心兰州分中心)

Dates

Publication Date

20260512

Application Date

20250114

Claims (3)

1. 1. The modified antiviral polypeptide based on Cecropin D (CD) is characterized in that the amino acid sequence of the antiviral polypeptide is shown as SEQ ID NO.2, SEQ ID NO.3 or SEQ ID NO. 4.
2. 2. Use of the antiviral polypeptide of claim 1 in the manufacture of a medicament for inhibiting highly pathogenic porcine reproductive and respiratory syndrome virus (high pathogenicity porcine reproductive and respiratory syndrome virus, HP-PRRSV).
3. 3. The use according to claim 2, wherein said antiviral polypeptide acts to inhibit HP-PRRSV replication by blocking a key step of HP-PRRSV invasion into cells.

Description

Antiviral polypeptide modified based on Cecropin D and application thereof in inhibiting porcine reproductive and respiratory syndrome virus infection Technical Field The invention relates to a novel antiviral polypeptide based on Cecropin D transformation, and also relates to application of the antiviral polypeptide in inhibiting porcine reproductive and respiratory syndrome virus infection, belonging to the technical field of medicines. Background Viral infection of pigs is one of the difficulties in the development of the global pig industry. The widely spread Porcine pathogenic viruses mainly comprise pseudorabies virus (Pseudorabies virus, PRV), porcine epidemic diarrhea virus (Porcine EPIDEMIC DIARRHEA virus, PEDV), porcine reproductive and respiratory syndrome virus (Porcine Reproductive and Respiratory Syndrome virus, PRRSV) and the like, and cause huge economic loss in the pig industry. Among them, PRRSV poses a great threat to the global pig industry, so vaccination is the primary means of controlling the disease. However, despite the many traditional blue-ear vaccines already in batch and wide clinical use, many challenges remain. Although the traditional inactivated vaccine has no biosafety risk, the neutralizing antibody level is low, the cell immunity cannot be induced, and multiple times of inoculation are needed. In contrast, live vaccines, although providing immune protection, are not sufficiently protected against heterologous strains, and have problems such as virulence reversion, recombination of vaccine strains with wild strains, and lack of markers. In addition, subunit vaccines and virus-like particle vaccines, while non-pathogenic, have limited protection against susceptible animals, while nucleic acid vaccines, while simple in production process, present potential biosafety risks, such as the possibility of integration of foreign DNA into the host genome. Meanwhile, the characteristics of high mutation rate and high recombination rate of PRRSV make the existing vaccine easy to fail, which further increases the difficulty of vaccine development. Due to the great challenges presented by PRRSV worldwide, more and more polypeptides with anti-PRRSV activity have been discovered and designed. The antimicrobial peptide is a small molecular protein which is widely used in animals, plants and microorganisms, has potential antibacterial, virus, fungus, tumor and parasite activities, can inhibit the replication of viruses by interfering with multiple stages of the life cycle of the viruses, and has various action mechanisms mainly comprising the destruction of viral envelope, the prevention of the binding of the viruses to host cells, the interaction with specific receptors of the host cells and the like. Cecropin D (CD) belongs to the Cecropin family, and [HULTMARK D,ENGSTROMA,BENNICH H,et al.Insect immunity:isolation and structure ofcecropin D and four minor antibacterial components from Cecropia pupae[J].Eur J Biochem,1982,127(1):207-17], is a multifunctional antibacterial peptide which is originally separated from the silkworm moth and has multiple functions of antivirus, antifungal, antitumor, immunoregulation and the like. According to the invention, firstly, the antiviral effect of Cecropin D is researched, then the anti-PRRSV activity of Cecropin D is further enhanced by introducing different cationic amino acids, and a novel technical means is provided for inhibiting PRRSV infection. Disclosure of Invention The invention aims to provide an antiviral polypeptide based on Cecropin D reconstruction and an application thereof in inhibiting porcine reproductive and respiratory syndrome virus infection, In order to achieve the above purpose, the invention adopts the following technical means: The invention designs and synthesizes Cecropin D and three derivatives CD-2 to CD-4 based on the balance of hydrophilicity and hydrophobicity. Wherein more positively charged lysine is introduced into CD-2 to enhance the interaction of the polypeptide and the membrane, more hydrophobic and positively charged tryptophan is introduced into CD-3, and valine (V) is replaced by phenylalanine (F) in CD-4 to promote the stability of the secondary structure. The results of HPLC and CD spectra show that the designed polypeptides are of higher purity and form a significant alpha helix structure. In particular, in the environment simulating cell membranes, the polypeptide shows remarkable structural change, and the polypeptide is verified to be capable of forming a stable secondary structure. Studies have shown that alpha helices can be inserted into the viral envelope, resulting in membrane disruption, interfering with its structural integrity, thus inhibiting viral infection [HUANGY,HE L,LI G,et al.Role ofhelicity ofalpha-helical antimicrobial peptides to improve specificity[J].Protein Cell,2014,5(8):631-42.HUAN Y,KONG Q,MOU H,et al.Antimicrobial Peptides:Classification,Design,Application and Research Progress