Key Laboratory for Industrial Biocatalysis of Ministry of Education, Institute of Biochemical Engineering, Department of Chemical Engineering, Tsinghua University, Haidian, Beijing 100084, People's Republic of China.
Carbohydr Polym. 2014 Jan 30;101:484-92. doi: 10.1016/j.carbpol.2013.09.052. Epub 2013 Sep 23.
Enzymatic depolymerization of heparin by heparinases is promising for production of low molecular weight heparins (LMWHs) as anticoagulants, due to its mild reaction conditions and high selectivity. Here, different heparinase combinations were used to depolymerize heparin. Heparinase I and heparinase II can depolymerize heparin more efficiently than heparinase III, respectively, but heparinase III was the best able to protect the anticoagulant activities of LMWHs. Heparinase III and heparinase I/II combinations were able to efficiently depolymerize heparin to LMWHs with higher anticoagulant activity than the LMWHs produced by the respective heparinase I and heparinase II. HepIII and HepI is the best combination for maintaining high anti-IIa activity (75.7 ± 4.21 IU/mg) at the same Mw value. Furthermore, considering both the changes in molecular weight and anticoagulant activity, the action patterns of heparinase I and heparinase II were found not to follow the exolytic and processive depolymerizing mechanism from the reducing end of heparin.
肝素酶对肝素的酶解作用有望用于生产低分子量肝素（LMWH）作为抗凝剂，因为其反应条件温和且具有较高的选择性。在这里，使用不同的肝素酶组合来对肝素进行解聚。肝素酶 I 和肝素酶 II 分别比肝素酶 III 更有效地对肝素进行解聚，但肝素酶 III 是保护 LMWH 的抗凝活性的最佳选择。肝素酶 III 和肝素酶 I/II 组合能够有效地将肝素解聚为具有比各自的肝素酶 I 和肝素酶 II 产生的 LMWH 更高抗凝活性的 LMWH。HepIII 和 HepI 是在相同 Mw 值下保持高抗 IIa 活性（75.7±4.21 IU/mg）的最佳组合。此外，考虑到分子量和抗凝活性的变化，发现肝素酶 I 和肝素酶 II 的作用模式不符合肝素从还原端进行外切和连续解聚的机制。
