3 results about "Serine protease activity" patented technology

This invention belongs to the field of biomedicine and relates to a procoagulant polypeptide TPTX and its applications. The procoagulant polypeptide TPTX of this invention can exert its procoagulant and hemostatic effects by specifically inhibiting plasmin activity. Experiments have shown that TPTX exhibits significant dose-dependent procoagulant and hemostatic effects in ferric chloride-induced mouse carotid artery thrombosis models, mouse liver hemorrhage models, mouse tail hemorrhage models, and mouse saphenous vein hemorrhage models, with effects superior to the positive control drug 6-aminocaproic acid. Simultaneously, TPTX can reduce the area of ​​atorvastatin-induced cerebral hemorrhage in zebrafish and improve their motor dysfunction. Mechanistic studies show that TPTX has an inhibitory constant Ki of 17.76 nM on plasmin and has no significant effect on the activity of seven other key serine proteases in the coagulation system, demonstrating a clear target and high selectivity. The procoagulant polypeptide of this invention can be used to prepare hemostatic drugs, possessing the advantages of high efficiency, clear target, and high selectivity, with broad prospects for clinical application.

The present invention relates to animal feed or animal feed additive comprising a polypeptide having protease activity and uses thereof. Specifically, the protease is a serine S1 protease from the genera Microspora, Terracoccus and Knoellia, all belonging to the family Microbacteriaceae of the suborder Micrococineae. These proteases have high activity over a broad pH range (pH 3-7) and are thus highly active during the entire passage through the digestive tract. It further relates to methods for producing these proteases as well as using the proteases to improve animal performance and the nutritional value of animal feed.

The invention belongs to the technical field of biology, and discloses an influenza virus sensitizing cell strain as well as a construction method and application thereof. The influenza virus sensibilization cell strain STX-TMP2 can stably express a human-derived influenza virus receptor ST6GAL1 and utilizes doxycycline to controllably induce a TMPRSS2 protein. The invention also discloses a preparation method of the influenza virus sensibilization cell strain STX-TMP2. The preservation number of the cell strain STX-TMP2 is GDMCC (China General Microbiological Culture Collection Center) NO: 67099; the cell strain has the following advantages: low toxicity: low background expression is realized through a Tet-on system, cytotoxicity caused by continuous high expression is significantly reduced, and long-term stable passage of the cell strain is ensured; controllability: the doxycycline can regulate and control the expression level and flexibly adapt to the production requirements of influenza virus vaccine strains; high efficiency: in an induction state, the cells have enough receptor expression and serine protease activity at the same time, and the amplification efficiency of the codon reprogramming virus with relatively low replication capacity is remarkably improved; wide applicability: the method is not only suitable for production of influenza virus vaccine strains with codon reprogramming, but also can be popularized to various production systems of attenuated influenza vaccines with relatively low replication ability.