(582cy) Controllable Depolymerization of Heparin By the Combinations of Heparinases I/II/III for the Production of Low Molecular Weight Heparins
Low molecular weight heparins (LMWHs) produced by the degradation of heparin has been widely used as anticoagulant. Enzymatic depolymerization of heparin by heparinases is a promising way for LMWHs production due to their mild reaction conditions, high selectivities and controllabilities. Here, different heparinases and their combinations were used to depolymerize heparin. The results demonstrated that heparinase I and heparinase II could depolymerize heparin efficiently but the anticoagulant activities of depolymerization products were destroyed significantly. Furthermore, the anticoagulant activity ratio (anti-factor Xa activity/anti-factor IIa activity) of depolymerization products increased significantly during the depolymerization process, which implied that the action patterns of heparinase I and heparinase II were not exolytic and processive depolymerizing mechanism from the reducing end of heparin, were reported for the first time. However, heparinase III couldn’t efficiently depolymerize heparin but could protect the anticoagulant activities of depolymerization products to the largest extent compared with heparinase I and heparinase II. The combination of heparinase III and heparinase I or heparinase II could exert the advantage of heparinase III to protect the anticoagulant activities to the largest extent during the depolymerization process and that of heparinase I or heparinase II to efficiently depolymerize heparin, and produce LMWHs with higher anticoagulant activities than that produced by Heparinase I and Heparinase II individually. The combination of heparinase III and heparinase I, exhaustive depolymerization by heparinase III followed by the controlled depolymerization by heparinase I, was the best combination for the production of LMWHs with high anticoagulant activities.