Heparanase as an Additional Tool for Detecting Structural Peculiarities of Heparin Oligosaccharides.

Alekseeva Alekseeva,Mazzini Mazzini,Urso Urso,Naggi Naggi

doi:10.3390/molecules24234403

Alekseeva Alekseeva, Mazzini Mazzini + Show 2 more

Open Access

https://doi.org/10.3390/molecules24234403

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Abstract

Due to the biological properties of heparin and low-molecular-weight heparin (LMWH), continuous advances in elucidation of their microheterogeneous structure and discovery of novel structural peculiarities are crucial. Effective strategies for monitoring manufacturing processes and assessment of more restrictive specifications, as imposed by the current regulatory agencies, need to be developed. Hereby, we apply an efficient heparanase-based strategy to assert the structure of two major isomeric octasaccharides of dalteparin and investigate the tetrasaccharides arising from antithrombin binding region (ATBR) of bovine mucosal heparin. Heparanase, especially when combined with other sample preparation methods (e.g., size exclusion, affinity chromatography, heparinase depolymerization), was shown to be a powerful tool providing relevant information about heparin structural peculiarities. The applied approach provided direct evidence that oligomers bearing glucuronic acid–glucosamine-3-O-sulfate at their nonreducing end represent an important structural signature of dalteparin. When extended to ATBR-related tetramers of bovine heparin, the heparanase-based approach allowed for elucidation of the structure of minor sequences that have not been reported yet. The obtained results are of high importance in the view of the growing interest of regulatory agencies and manufacturers in the development of low-molecular-weight heparin generics as well as bovine heparin as alternative source.

Highlights

Heparin is a widely used anticoagulant and antithrombotic drug which structurally represents a highly sulfated linear polydisperse glucosaminoglycan (GAG) that primarily consists of a repeating2-O-sulfated iduronic acid (I2S ) and glucosamine-N,6-O-disulfate (ANS6S )
Despite ion pair reversed-phase (IPRP) UHPLC separation mode having been previously shown to provide a good resolution between these isomers [12], the method transfer to a preparative HPLC scale caused a dramatic decrease in their separation
The combination of enzymatic methods, the UHPLC separation mode and the introduction of the on-line collision ion dissociation (CID) mass spectrometry (MS)/MS analysis did provide some relevant data for the elucidation of the isomeric structures

Summary

Introduction

Heparin is a widely used anticoagulant and antithrombotic drug which structurally represents a highly sulfated linear polydisperse glucosaminoglycan (GAG) that primarily consists of a repeating2-O-sulfated iduronic acid (I2S ) and glucosamine-N,6-O-disulfate (ANS6S ). Heparin structural complexity is further increased by the presence of glucuronic acid (G) and N-acetyl-glucosamine (ANAc ) as well as other minor structures, such as 2-O-sulfated glucuronic acid (G2S ), linkage region (LR), 3-O-sulfated glucosamine-N-sulfate (ANS3S(6S) ) [1,2,3]. The latter, when preceded by G, is a marker of antithrombin binding region (ATBR) (ANX6S –G–ANS3S6S –I2S –ANS6S ; X = Ac or SO3 ) essential for high anticoagulant and antithrombotic activity of heparin [4,5,6].

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