Structural features and inactivation of coagulation proteases of a sulfated polysaccharidic fraction from Caulerpa cupressoides var. lycopodium (Caulerpaceae, Chlorophyta) - doi: 10.4025/actascitechnol.v35i4.16709

Abstract

Studies on biopolymers from macroalgae suggested sulfated polysaccharides (SPs) as research agents to investigate events related to haemostasis. Caulerpa cupressoides var. lycopodium is a marine green alga containing three SPs fractions (SP₁, SP₂ and SP₃). SP₂ had anticoagulant (in vitro) and anti- and prothrombotic (in vivo) actions; however, its effect on the coagulation system is not fully understood. This study aimed to determine the infrared (IR) spectroscopy, chemical composition (CC), elemental microanalysis (EM), molecular weight (MW) and the effect on coagulation proteases of SP₂. The presence of sulfate ester, galactose-6-sulfate, uronic acid and glycoside linkages for IR spectrum; contents of sulfate (28%), total sugars (40%) and uronic acids (7.18%) for CC; and content of carbon (21.98%), sulfate (4.27%), nitrogen (1.3%) and hydrogen (4.86%) for EM were obtained. The average molecular weights of four different SPs (SP-1, SP-2, SP-3 and SP-4) subfractions from the SP₂ ranged from ~ 8 to >100 kDa. SP₂ was tested on coagulation proteases (thrombin and factor Xa) in the presence of antithrombin (AT) and heparin cofactor II (HCII) using human plasma, being both thrombin and factor Xa target proteases inhibited, but requiring a concentration of about 2.5-fold higher of HCII than the thrombin inactivation by AT.