Difference between revisions of "Part:BBa K4169000"

Revision as of 19:09, 11 October 2022

Nattokinase gene with pelB

Signal peptide gene of PelB can direct aprN to Escherichia coli periplasmic membrane. The propeptide has been proved to function as an intramolecular chaperone and is essential for guiding the correct folding of the linked protein to its mature form. The nattokinase has potent fibrinolytic activity, which could enhance and prolong fibrinase in the plasma. Based on its food origin and relatively strong fibrinolytic activity, it a possible safe and efficient medicine for use in the prevention of thrombosis diseases.

Usage and Biology

Nattokinase had potent fibrinolytic activity, which could be enhanced and prolonged in the plasma when it was taken orally. Based on its food origin and relatively strong fibrinolytic activity, nattokinase has advantages over other commercially used medicine in its preventative and prolonged effects, convenient oral administration, and stability in the gastrointestinal tract^[1]. As a basic serine protease, nattokinase has strong fibrinolytic and thrombolytic activities. In our project, nattokinase was used to dissolve thrombus formed in blood vessels and prevent thrombus formation when thrombus is not formed. The mechanism of nattokinase has the following five points:(1) Nattokinase activates the conversion of prourokinase to urokinase, together with tissue-type plasminogen to activate plasminogen to generate plasmin ^[2]. (2) Nattokinase promotes plasminogen transformation by stimulating vascular endothelial cells to produce tissue plasminogen activator (t-PA) ^[3]. (3) Nattokinase also has the ability to degrade inactivated plasminogen activator type I inhibitor, promote the synthesis of more t-PA and urokinase, and indirectly promote thrombolysis ^[4]. (4) Nattokinase administration is capable of reducing the concentration of plasma coagulation factor VII and coagulation factor VIII that can increase the risk of cardiovascular diseases by triggering the coagulation cascade reaction ^[5]. (5) Nattokinase prevents the formation of thromboxane and significantly inhibits platelet aggregation mediated by collagen and thrombin, thereby delaying the formation of thrombi after oxidative arterial wall injury, and promoting the detachment of thrombi from blood vessel walls, so as to reduce endothelial damage and vascular endothelial thickening caused by thrombi^[6][7].

Structure

Mature peptides consist of 9 α-helixes, 9 β-sheets and 2 Ca²⁺ binding sites for structural stability. The catalytically active center of nattokinase consists of a conserved catalytic triad (Asp32, His64, Ser221), while its substrate-binding center contains three conserved amino acids (Ser125, Leu126, Gly127). The Propeptide of Nattokinase Is Involved in the Correct Folding of Nattokinase as an Intramolecular Chaperone. The signal peptide gene of PelB can direct aprN to Escherichia coli periplasmic membrane and help mature nattokinase secretory expression.^[8]

Characterization

SDS-PAGE

First, we identified nattokinase by SDS-PAGE. We identified nattokinase produced by optimal expression conditions mentioned in the literature and it produced by our desired expression conditions.

Sequence and Features