Hyaluronidases

Literature References: Enzymes which have in common the cleavage of glycosidic bonds of hyaluronic acid, q.v., and, to a variable degree, of some other acid mucopolysaccharides of connective tissue. The skin is probably the largest store of hyaluronidase in the body; the enzyme although generally present in an inactive form, may be supposed to regulate the velocity of water and metabolite exchange by decreasing the viscosity of the intercellular matrix. Also has a physiological role in fertilization: The sperm is rich in the enzyme and can thus advance better in the cervical canal and reach the ovum. Found in the type II pneumococci, in group A and C hemolytic streptococci, Staphylococcus aureus and Clostridium welchii: Linker et al., J. Biol. Chem. 219, 13 (1956); in heads of leeches: Linker et al., Nature 180, 810 (1957); in snake venoms: Favilli, ibid. 145, 866 (1940); in testes: Hahn, Biochem. Z. 315, 83 (1943); Högberg, Acta Chem. Scand. 8, 1098 (1954). Biochemical properties: D. Platt, Arzneim.-Forsch. 20, 1836 (1970). Review: Meyer, Rapport in Adv. Enzymol. 13, 199-236 (1952); Meyer et al., The Enzymes vol. 4, P. D. Boyer et al., Eds. (Academic Press, New York, 2nd ed., 1960) pp 447-460; Meyer, ibid. vol. 5 (3rd ed., 1971) pp 307-320. Reviews of clinical trials in myocardial infarction: G. S. May et al., Prog. Cardiovasc. Dis. 25, 335-359 (1983); A. B. Saunders, Emerg. Med. Clin. North Am. 6, 361-372 (1988). Hyaluronidase manufacturers define their product in terms of turbidity-reducing (TR) units or in viscosity units. Prepd solns for injection usually contain 150 turbidity-reducing units or 500 viscosity units dissolved in 1 ml of isotonic NaCl soln.