Molecular characteristics of polysulfated fractions from the green seaweed Caulerpa cupressoides and actions on thrombin generation in vitro
Rodrigues, José Ariévilo GurgelBenevides, Norma Maria BarrosTovar, Ana Maria FreireMourão, Paulo Antônio de Souza
Caulerpa cupressoides produces sulfated polysaccharides (Cc-SPs) with serpin-dependent anticoagulant effect, but their actions on thrombin generation (TG) are unknown. This study aimed to partially characterize Cc-SPs and examine their potential as modulators of TG. Infrared analysis characterized extract containing three ulvan fractions (Cc-SP1, -SP2 and -SP3) separated by DEAEcellulose chromatography, with differences in the relative proportions of sulfate (10.99-18.38%) and total sugars (46.59-51.12%), without presenting proteins. Charge density patterns and nonSPs varying from 8 to > 100 kDa on agarose and polyacrylamide gel electrophoresis by sequential staining with toluidine blue and stains-all were also confirmed by gel permeation chromatography. The molecular weight of Cc-SP2 was not altered after treatment with 0.4 M HCl up to 5 h. Only Cc-SP2 altered the activated partial thromboplastin time (15 ± 0.3 IU) vs. heparin (193 IU) and abolished at high concentrations (> 4.1 μg) TG by intrinsic pathway in 60-fold diluted human plasma, while at 4.1 μg attenuated TG by 33.87% delaying the lag phase (32 min.) vs. control (28 min.). Cc-SP2 induced concentration-dependent TG in system without cephalin. Heparin abolished TG at 4.15-fold lower amount, but did not stimulate TG. Therefore, Cc-SPs express dual effects on thrombosis in vitro.(AU)
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