HYALURONIDASES OF BACTERIAL AND ANIMAL ORIGIN

Area of Science:

• Biochemistry
• Enzymology
• Microbiology

Background:

• Hyaluronidase is an enzyme that degrades hyaluronic acid, a key component of connective tissues.
• Its presence and activity have been noted in various bacterial strains (pneumococci, hemolytic streptococci) and animal tissues (leech, testis, spleen, skin).

Purpose of the Study:

• To investigate the presence and characteristics of hyaluronidase in different microbial and animal sources.
• To compare the enzymatic activity, substrate specificity, and optimal conditions of hyaluronidase from various origins.
• To explore the relationship between hyaluronidase and the 'spreading factor' phenomenon.

Main Methods:

• Viscosimetric assays using hyaluronic acid-rich fluids as substrates.
• Hydrolysis of pure hyaluronic acid to identify breakdown products.
• Enzyme preparation from various sources including bacteria (pneumococci, streptococci), leech, testis, spleen, and skin.
• pH optimum determination for different hyaluronidase preparations.
• Comparison of hyaluronidase activity with hydrolysis of other polysaccharides like beta-glucuronides and chondroitinsulfuric acid.

Main Results:

• Hyaluronidase was detected in all tested pneumococcal strains and some hemolytic streptococci, with significant variability in concentration and lability.
• Bacterial and leech hyaluronidases showed optimal activity around pH 5.8, while testis hyaluronidase had a primary optimum at pH 4.4 and a secondary one at pH 5.8.
• Testis hyaluronidase exhibited a more marked depolymerizing action than pneumococcal hyaluronidase, suggesting the presence of multiple enzyme types or mechanisms.
• Hyaluronidases from different sources also hydrolyzed other acidic polysaccharides, indicating broader substrate specificity or the presence of associated enzymes.
• The study observed a potential link between hyaluronidase and the 'spreading factor', though conclusive evidence was hindered by inconsistent findings in streptococcal strains.

Conclusions:

• Hyaluronidase activity is widespread but variable in different bacterial and animal sources.
• The depolymerization of hyaluronic acid likely involves a single enzyme, but different sources may possess distinct hyaluronidases with varying properties and substrate specificities.
• The exact relationship between hyaluronidase and the 'spreading factor' requires further investigation, potentially involving reversibly inactive enzyme forms.