Analysis of the proteolytic system of Streptococcus thermophilus strains CS5, CS9, CS18 and CS20

Background: Antiplatelet, anticoagulant and fibrinolytic activities of stem bromelain (EC 3.4.22.4) are well described, but more studies are still required to clearly define its usefulness as an antithrombotic agent. Besides, although some effects of bromelain are linked to its proteolytic activity, few studies were performed taking into account this relationship. Objective: We aimed at comparing the effects of stem bromelain total extract (ET) and of its major proteolytic compounds on fibrinogen, fibrin, and blood coagulation considering the proteolytic activity. Methods: Proteolytic fractions chromatographically separated from ET (acidic bromelains, basic bromelains, and ananains) and their irreversibly inhibited counterparts were assayed. Effects on fibrinogen were electrophoretically and spectrophotometrically evaluated. Fibrinolytic activity was measured by the fibrin plate assay. The effect on blood coagulation was evaluated by the prothrombin time (PT) and activated partial thromboplastin time (APTT) tests. Effects were compared with those of thrombin and plasmin. Results: Acidic bromelains and ananains showed thrombin-type activity and low fibrinolytic activity, with acidic bromelains being the least effective as anticoagulants and fibrinolytics; while basic bromelains, without thrombin-like activity, were the best anticoagulant and fibrinolytic proteases present in ET. Procoagulant action was detected for ET and its proteolytic compounds by the APTT test at low concentrations. The measured effects were dependent on proteolytic activity. Conclusion: Two sub-populations of cysteine proteases exhibiting different effects on fibrin (ogen) and blood coagulation are present in ET. Using well characterized stem bromelain regarding its proteolytic system is a prerequisite for a better understanding of the mechanisms underlying the bromelain action.

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Honey Bee Proteolytic System and Behavior Parameters under the Influence of an Electric Field at 50 Hz and Variable Intensities for a Long Exposure Time

Animals ◽

10.3390/ani11030863 ◽

2021 ◽

Vol 11 (3) ◽

pp. 863

Author(s):

Paweł Migdał ◽

Agnieszka Murawska ◽

Aneta Strachecka ◽

Paweł Bieńkowski ◽

Adam Roman

Keyword(s):

Electromagnetic Field ◽

Honey Bee ◽

Protease Activity ◽

Lower Number ◽

Behavioral Analysis ◽

Control Group ◽

Alkaline Proteases ◽

Proteolytic System ◽

Wing Movement ◽

And Behavior

The effect of an artificial electromagnetic field on organisms is a subject of extensive public debate and growing numbers of studies. Our study aimed to show the effect of an electromagnetic field at 50 Hz and variable intensities on honey bee proteolytic systems and behavior parameters after 12 h of exposure. Newly emerged worker bees were put into cages and exposed to a 50 Hz E-field with an intensity of 5.0 kV/m, 11.5 kV/m, 23.0 kV/m, or 34.5 kV/m. After 12 h of exposure, hemolymph samples were taken for protease analysis, and the bees were recorded for behavioral analysis. Six behaviors were chosen for observation: walking, flying, self-grooming, contact between individuals, stillness, and wing movement. Bees in the control group demonstrated the highest number of all behavior occurrences, except flying, and had the lowest protease activity. Bees in the experimental groups showed a lower number of occurrences of walking, self-grooming, and contacts between individuals than the control bees and had significantly higher protease activity than the control bees (except that of alkaline proteases in the 23.0 kV/m group).

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