The fibrinolytic activity in Korean traditional fermented food, Jotgal (pickled fish) was identified. Though the fibrinolytic activity could vary in different kinds of Jotgal, this activity seems to be produced by microorganisms during the natural fermentation stage. From Gonjaengijot (pickled opossum shrimp), two novel fibrinolytic enzymes named by JP‐I and JP‐II, have been purified by ethanol precipitation, Bio‐GEL P‐100 gel filtration, and DEAE‐cellulose ion‐exchange chromatography. Compared to the crude enzyme extract, the specific activity of the JP‐I and JP‐II increased 258, 85‐fold with the recovery of 22.1, 8.5%, respectively. The molecular weights of both enzymes were estimated as 36 kDa on sodium dodecyl sulphate‐polyacrylamide gel electrophoresis (SDS–PAGE). The optimal condition for fibrinolytic activity of JP‐I was at 50°C and pH 8.1, while that of JP‐II was at 45°C and 9.9. Both enzymes were stable at a broad range of pH (5.0 to 10.5) and have metalloprotease nature. From these results, it concludes that these enzymes could be a novel potent thrombolytic agent. Practical applications The fibrinolytic enzyme is one of the clinical agents for cardiovascular diseases which is the leading cause of morbidity and mortality worldwide with 17 million deaths every year. A variety of fibrinolytic enzymes are found and characterized from various sources such as plants, animals, and microorganisms, and new sources for fibrinolytic enzymes continue to be explored. Jotgal, widely used in Korean people's diet, is a traditional Korean seafood prepared from many different types of fishes, fish eggs, fish intestines, and shellfishes. Through an amount of research, some of fibrinolytic enzymes were found and purified from Jotgal, however, no studies have been done on fibrinolytic enzyme from opossum shrimp. In this study, the purification, enzymatic characteristics, and fibrinolytic activity of the proteases, originated from Korean traditional fermented food, Jotgal were reported. These enzymes could be novel potent thrombolytic agent.

Background: The focus of this study was the selection of a single chain variable fragment antibody (scFv) against subtilisin BRC, a fibrinolytic enzyme using phage display, and to characterize the interaction between the antibody and subtilisin BRC. Methods: The subtilisin BRC-specific phage clones were selected using Griffin.1 scFv phage library and sequenced. The gene of subtilisin BRC-specific scFv (scFv-BRC) from selected phage clone was expressed in E. coli and scFv-BRC was characterized. Molecular modeling of the three-dimensional (3D) structures of scFv-BRC was performed using MODELLER 9.19 modeling software and assessed by PROCHEK. Molecular docking of subtilisin BRC with scFv-BRC was carried out using PATCHDOCK. Results: The size of scFv-BRC gene is 635bp and it consists of 54bp of heavy chain region (VH), 336bp of light chain region (VL), 45bp of a linker. scFv-BRC was actively expressed by E. coli expression vector pET28a-scFv in E. coli BL21 (DE3), and the amount of expressed scFv-BRC was about 50 mg/L. Its molecular weight is ~26kDa. The CDR domain of scFv-BRC consists of 6 amino acids in CDR L1, 3 amino acids in CDR L2 and 9 amino acids in CDR L3. Docking results of subtilisin BRC and scFv-BRC showed global energy of - 56.29 kJ/mol. Furthermore, the results showed that amino acid residues in subtilisin BRC for binding with scFv-BRC are Tyr6, Ser182, Ser204, and Gln206. Conclusion: scFv against subtilisin BRC selected using phage display showed relatively strong binding energy with subtilisin BRC. The amino acid residues in subtilisin BRC for binding with scFv-BRC are not relevant to that in subtilisin BRC for binding with its substrates. These results suggested that scFv-BRC can be used as a ligand for detection and affinity purification of subtilisin BRC.

Background: The Klf6 gene, which belongs to Krüppel-like family of C2H2 zinc finger transcription factors, is greatly related to tumorigenesis via a high rate of somatic mutation in the carcinomas of prostate, liver, colon, stomach, lung, neck, pituitary, and nervous system: Furthermore, the pathways regulating the expressions of Klf6 splice variants termed Klf6-SV1,-SV2, and-SV3 remain obscure although their functional outcomes have been clear. In this study, the functional roles of Klf6 variants in the inhibition of cell proliferation induced by the disruption of Klf6related super enhancer in human hepatoma (HepG2) cells were evaluated. Results: As a result, the disruption of Klf6-related super enhancer not only induced the upregulation of Klf6-SV2 but also led to a significant reduction of proliferation in HepG2 cells. In addition, the disruption of Klf6-related super enhancer led to the induction of p21 and Bax genes mediated by the upregulation of Klf6-SV2. Conclusion: In conclusion, it was demonstrated that Klf6-related super enhancer modulates cell proliferation via the regulation of Klf6-SV2 expression in human hepatoma (HepG2) cells. The results provide the functional significance of Klf6-related super enhancer in understanding the transcriptional regulation mechanism of Klf6.

Background: The focus of this study was to prepare and characterize the single-chain variable fragment antibody (scFv)-coupled immunoaffinity column for purification of subtilisin BRC. Methods: The scFv against subtilisin BRC was immobilized onto CNBr-activated Sepharose 4B. Adsorption isotherm for subtilisin BRC on scFv-BRC-coupled Sepharose 4B was obtained and calculated the maximum binding capacity. The extraction conditions including eluting solution, the concentration of eluting solution and flow rate were optimized. Under the optimized eluting conditions, the dynamic binding capacity of the immunoaffinity column was determined. Results: The scFv-BRC-coupled Sepharose 4B for immunoaffinity purification of subtilisin BRC was prepared. The coupling efficiency was about 78.4%, e.g. about 8 mg of scFv-BRC was covalently coupled to 1 g CNBr-activated Sepharose 4B. The maximum equilibrium binding capacity (qm) and dissociation constant (Kd) of the immunoaffinity column for subtilisin BRC were 3.01 mg/mL and 0.465 mg/mL, respectively. The immunoaffinity chromatography conditions were optimized and the subtilisin BRC was purified 3.29-fold with 55.6%. Conclusion: The subtilisin BRC was effectively purified with high purity using scFv-BRC-coupled Sepharose 4B and the dynamic binding capacity of the column was determined. These results suggested that scFv-BRC can be used as a ligand for affinity purification of subtilisin BRC.

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