New Fibrinogenases Isolated From Marine Hydrobiont Adamussium colbecki

Aims: Enzymes that affect hemostasis have been isolated from different sources. Fibrinogenolytic
enzymes because of their role in dissolving of blood clots as well as preventionof their formation have
attracted special medical and scientific attention. The main goal of current research was to analyze
marine hydrobionts (an example of the Antarctic scallop Adamussium colbecki) of the Antarctic region
on the presence of potential fibrinogenolytic enzymes.
Methodology: The fraction that consists of fibrinogenases was obtained by affinity chromatography
on Blue Sepharose column. SDS-PAGE was applied for the determination of protein composition in
the obtained fraction. The proteolytic activity was monitored by the zymographic technique.
Fibrinogenolytic activity and activity toward collagen were assessed by incubation of samples with
fibrinogen or collagen, respectively followed by SDS-PAGE analysis. To test for substrate specificity,
the fraction of fibrinogenases was incubated with p-nitroanilide chromogenic peptides such as S-2366,
S-2238, S-2251, S-2222. The fraction of fibrinogenaseswas preincubated with protease inhibitors
EDTA, PMSF, and enzymatic activity was measured.
Results:The results clearly indicated the presence of enzymes with activity toward fibrinogen in the
extract of A. colbecki. Zymography analysis detected the presence of active enzymes in the region of
27-30 kDa. The fibrinogen cleavage pattern was analyzed by SDS-PAGE under reducing conditions
has revealed time- and dose-dependent hydrolysis of fibrinogen. The susceptibility of fibrinogen
chains to proteolytic degradation by fibrinogenases from A. colbecki was different. The enzymes
preferentially hydrolyzed the Aα-chain; they also cleaved the Bβ-chain but at a slower rate. Collagen
was found to be resistant to the action of the fibrinogenases under similar experimental conditions.
Fibrinogenases from A. colbecki hydrolyzed chromogenic substrates as S-2238, S-2251, S-2222 and
S-2366 but with different specificity. Specific protease inhibitors PMSF and EDTA were used to
identify the nature of fibrinogenases present in the tissue of hydrobiont. On the basis of this analysis,
the fraction of fibrinogenases from A. colbecki consisted of serine proteases as well as
metalloproteases.