Mannose 2, 3, 4, 5, 6-O-pentasulfate (MPS): a partial activator of human heparin cofactor II with anticoagulation potential

Abstract

Thromboembolic diseases are a major cause of mortality in human and the currently available anticoagulants are associated with various drawbacks, therefore the search for anticoagulants that have better safety profile is highly desirable. Compounds that are part of the dietary routine can be modified to possibly increase their anticoagulant potential. We show mannose 2,3,4,5,6-O-pentasulfate (MPS) as a synthetically modified form of mannose that has appreciable anticoagulation properties. An in silico study identified that mannose in sulfated form can bind effectively to the heparin-binding site of antithrombin (ATIII) and heparin cofactor II (HCII). Mannose was sulfated using a simple sulfation strategy-involving triethylamine-sulfur trioxide adduct. HCII and ATIII were purified from human plasma and the binding analysis using fluorometer and isothermal calorimetry showed that MPS binds at a unique site. A thrombin inhibition analysis using the chromogenic substrate showed that MPS partially enhances the activity of HCII. Further an assessment of in vitro blood coagulation assays using human plasma showed that the activated partial thromboplastin time (APTT) and prothrombin time (PT) were prolonged in the presence of MPS. A molecular dynamics simulation analysis of the HCII-MPS complex showed fluctuations in a N-terminal loop and the cofactor binding site of HCII. The results indicate that MPS is a promising lead due to its effect on the in vitro coagulation rate.

Communicated by Ramaswamy H. Sarma

Keywords:

• Anticoagulant
• serpin
• thrombosis
• antithrombin
• heparin cofactor II
• sulfated mannose

Disclosure statement

The authors have no conflict of interest to declare.

Ethical statement

All the experimental protocols were approved by the Institutional ethical committee of the Jamia Millia Islamia.

Author contributions

M.A.J designed the study. Q.R, N.G and I.A synthesized and characterized the MPS. B.A.K and S.B did anticoagulant assays. S.B and S. F did binding studies and kinetic assays. S.A and S.B. helped with in silico studies. A.P. and A.M.L. conducted MD simulation. M.A.J. and S.B wrote the manuscript. All the authors read and approved the manuscript.

Additional information

Funding

This work was supported by grants from (DST-SERB-CRG/2020/004638) and Department of Biotechnology (BT-PR23265/10/1585/2017), Govt. of India. QR was supported by CSIR-SRF, NG is a DST-INSPIRE Faculty, SB, SF and SA are supported by DBT fellowships and IA is an ICMR-SRF.