Provided is a thrombolytic agent for ‘intravascular thrombus’, and more particularly, to a thrombolytic agent having a thrombo-recognition domain and a thrombolytic domain. It also relates to a polypeptide for thrombolysis of an intravascular thrombus, a gene for that polypeptide, and a pharmaceutical composition containing the same. The polypeptide that recognizes ‘intravascular thrombus’ and dissolves thrombus of the present invention is characterized in that it consists of a thrombolytic domain comprising the amino acid sequence set forth in SEQ ID NO: 1 or SEQ ID NO: 2 and a thrombo-recognition domain comprising the amino acid sequence set forth in SEQ ID NO: 3 or SEQ ID NO: 4. According to the present invention, the polypeptide for dissolving thrombus by recognizing ‘intravascular thrombus’ dissolves thrombus in the blood of a mammal without serious bleeding side effects has a preventive and therapeutic effect on thrombosis, thus preventing thrombosis and related diseases.

The invention provides protease genes which are regulated in a specific manner during curing of tobacco plants material and which affect the flavour of cured tobacco.

A method for treatment of one or more toxin(s) in a subject, that includes administering to the subject a therapeutically effective amount of a serine protease that enzymatically cleaves certain toxins. Also, a method for preventing disease progression in a subject infected by Clostridioides difficile (CD), diarrhea, or infectious colitis, which includes administering to the subject a therapeutically effective amount of the protease. The protease retains its activity up to 65 C. Treatment with the protease in mice infected with CD conferred a 10-fold survival benefit compared to mice infected with CD and untreated.

An engineered strain for improving tryptophan production and a construction method and use thereof are provided. By screening out a strain capable of tolerating high-concentration tryptophan and performing genomic sequencing and protein sequence analysis on the strain, it is found that certain proteins in the strain undergo point mutations and these mutations are capable of enhancing tryptophan production. To increase tryptophan production, protein sequences encoded by fadR or pepD genes in a parent strain are modified. These modifications result in an engineered strain with significantly higher tryptophan production compared to the parent strain. Under scaled-up production conditions, the tryptophan production reaches 62.385.80 g/L in a 5 L fermenter, with a glucose-to-tryptophan yield of 24.1%. Compared to an original strain, tryptophan production increases by 1.48-fold, and the glucose-to-tryptophan yield improves by 1.26-fold. The biological materials and its use belong to the technical field of molecular biology and possess broad practical application value.