Leech, hyaluronidase

Two further points of interest with regard to the specificity of /3-glu-curonidase are raised by recent reports that leech hyaluronidase is a poly-/ -glucuronidase,211 and that hydrolysis of certain mucopolysaccharides yielded some L-iduronic acid212 oligosaccharides containing this uronic acid resisted hydrolysis by /3-glucuronidase.209... 

Heparitin sulfate is composed of D-glucuronic acid, n-glucosamine, acetyl, and sulfate residues in approximately equimolar ratio (J12). The structure of heparitin sulfate still awaits final elucidation, but it may be distinguished from other sulfated mucopolysaccharides by means of its high positive rotation, electrophoretic behavior, and resistance to testicular, bacterial, and leech hyaluronidases. Final identification, however, usually requires its isolation and analysis. 

In several experiments, intraperitoneal injections of leech extracts or of another hyaluronidase were found to lessen the susceptibility to hemolytic streptococci intraperitoneally administered. Therefore, it was suggested that hyaluronate in the streptococcal capsules protects the organisms and is responsible for their greater virulence. These results were not confirmed in a similar experiment by McClean. Subsequently, McClean injected a hyaluronidase into mice infected with streptococci and found that the bacterial capsules were initially removed but returned after about one and a half hours. Similarly, Kass and Seastone found that hyaluronidase injections had no effect on the virulence of pneumococci in mice. ... 

There are hyaluronidases that function as endo-(3-glucuronidases that cleave the (1 3)-P glycosidic bonds. However, no sequence data on these enzymes is yet available. These enzymes are characteristic of annelids such as leeches e.g., Herudo medicinalis [196-198], and certain crustaceans [199]. They utilize the hydrolysis mechanism, and thus resemble the vertebrate enzymes more closely than the prokaryotic hyaluronidases. 

M. Budds, J. Edwards, A. H. Olavesen, and P. Gacesa. A comparison of the properties of the hyaluronidases from a temperate and a tropical species of leech. Comp. Biochem. Physiol. 576 497 (1987). 

A. Lingo-, K. Meyo, and P. Hoffman. The production of hyaluronate oligosaccharides by leech hyaluronidase and alkali. J. Biol. Chem. 235 924 (1960). 

Endo-]3-glucuronidase types of hyaluronidase (EC 3.2.1.36) found in leeches, crustaceans (Karlstam et al, 1991) [121] and some parasites, generate tetra-and hexasaccharide end-products. 

Type 2. Hyaluronidase from leech saliva. The final products of hydrolysis by both Type 1 and Type 2 hyaluronidases are tetrasaccharides, which possess amino sugar at their reducing terminus and are activated with the enzymes of the Type 1. Additionally, the testicular and lyzosomal hyaluronidases are capable of trans-glycosylase activity and... 

While all hyaluronidases can bring about the depolymerization of hyaluronic acid, the individual enzymes differ considerably in specificity, reaction mechanism, and the products of the catalyzed reaction (Meyer el al., 1960 Gibian, 1966). Apart from an enzyme from leech (an endo- glucuronidase) (Meyer el al., 1960), all other known hyaluronidases act upon the ondohexosarainide linkages. 

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