Rapid Separation and Display of Active Fibrinogenolytic Agents in Sipunculus nudus through Fibrinogen-Polyacrylamide Gel Electrophoresis.

Fibrinogenolytic agents that can dissolve fibrinogen directly have been widely used in anti-coagulation treatment. Generally, identifying new fibrinogenolytic agents requires the separation of each component first and then checking their fibrinogenolytic activities. Currently, polyacrylamide gel electrophoresis (PAGE) and chromatography are mostly used in the separating stage. Meanwhile, the fibrinogen plate assay and reaction products based PAGE are usually adopted to display their fibrinogenolytic activities. However, because of the spatiotemporal separation of those two stages, it is impossible to separate and display the active fibrinogenolytic agents with the same gel. To simplify the separating and displaying processes of fibrinogenolytic agent identification, we constructed a new fibrinogen-PAGE method to rapidly separate and display the fibrinogenolytic agents of peanut worms (Sipunculus nudus) in this study. This method includes fibrinogen-PAGE preparation, electrophoresis, renaturation, incubation, staining, and decolorization. The fibrinogenolytic activity and molecular weight of the protein can be detected simultaneously. According to this method, we successfully detected more than one active fibrinogenolytic agent of peanut wormhomogenate within 6 h. Moreover, this fibrinogen-PAGE method is time and cost-friendly. Furthermore, this method could be used to study the fibrinogenolytic agents of the other organisms.

Fibrinolytic drugs induced hemorrhage: mechanisms and solutions.

Thrombosis has been emerging as a major global life-threatening issue with high mortality and serious complications, especially in the post-COVID-19 era. Compared with the commonly used plasminogen activators thrombolytic drugs, fibrinolytic drugs are no longer heavily dependent on the patients' own plasminogen, which are poorly expressed in most patients. As a novel "direct acting" thrombolytic agent, fibrinolytic drugs are considered to have stronger thrombolytic efficacy and safety than the widely used plasminogen activators. However, the risk of their hemorrhage remains a major concern. Herein, the molecular mechanisms and solutions were summarized for the first time based on the systematic review of the latest developments, which could shed new light on the development of novel safety fibrinolytic drugs in the future.

Affinity Purification of a Fibrinolytic Enzyme from Sipunculus nudus.

The fibrinolytic enzyme from Sipunculus nudus (sFE) is a novel fibrinolytic agent that can both activate plasminogen into plasmin and degrade fibrin directly, showing great advantages over traditional thrombolytic agents. However, due to the lack of structural information, all the purification programs for sFE are based on multistep chromatography purifications, which are too complicated and costly. Here, an affinity purification protocol of sFE is developed for the first time based on a crystal structure of sFE; it includes preparation of the crude sample and the lysine/arginine-agarose matrix affinity chromatography column, affinity purification, and characterization of the purified sFE. Following this protocol, a batch of sFE can be purified within 1 day. Moreover, the purity and activity of the purified sFE increases to 92% and 19,200 U/mL, respectively. Thus, this is a simple, inexpensive, and efficient approach for sFE purification. The development of this protocol is of great significance for the further utilization of sFE and other similar agents.