The proteolytic activity of the crude enzyme extracts of Baltic cod ( Gadus morhua) alimentary tract

Summary The crude enzyme extract from Baltic cod alimentary tract had maximum activity of aspartic proteinases towards haemoglobin at pH 2.0 and 3.4, and of serine proteinases with casein as the substrate at pH 8.3 and 10.4. With bovine myofibrils as the substrate the proteolysis at pH 5.0‐8.0 was m...

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Bibliographic Details
Published in:International Journal of Food Science & Technology
Main Authors: KOLODZIEJSKA, ILONA, MARCINKOWSKA, ANNA, KARAMAĆ, MAGDALENA
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 1995
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Online Access:http://dx.doi.org/10.1111/j.1365-2621.1995.tb01367.x
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2621.1995.tb01367.x
http://onlinelibrary.wiley.com/wol1/doi/10.1111/j.1365-2621.1995.tb01367.x/fullpdf
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Summary:Summary The crude enzyme extract from Baltic cod alimentary tract had maximum activity of aspartic proteinases towards haemoglobin at pH 2.0 and 3.4, and of serine proteinases with casein as the substrate at pH 8.3 and 10.4. With bovine myofibrils as the substrate the proteolysis at pH 5.0‐8.0 was maximum at the lowest and highest pH values. the optimum temperature for the proteolytic activity at pH 3.4 and 10.4 was 30–45°C and at pH 8.3 it was 40–50°C. Heating the crude extract for 10 min at pH 3.4,8.3, and 10.4 in the absence of the substrate had no effect on the activity of the acid and alkaline proteinases up to about 35–40°C. the stability at higher temperature decreased gradually and total inactivation occurred at 55–60°C. In the pH range 5.5–7.5 the proteolytic activity against bovine myofibrils was low at 0°C but brought about significant loss of myosin heavy chain at 20°C.