Hyaluronidase Classification

Recently, numerous smdies regarding the localization, structure and properties of hyaluronan have been published [41 ]. However, the systematization initially proposed by K. Meyer is still relevant. Based on Meyer s classification [42], hyaluronidases could be divided into three types based on source enzyme criteria, the type of the reaction that the enzyme could catalyse and the final 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 

Type 3. Microbial hyaluronidases (e.g. Streptococcus hyaluronidase). Microbial hyaluronidases hydrolyse p-N-acetylaminoglycoside bonds of a substrate and simultaneously dehydrate the residue of uronic acid at the non-reducing terminus of the molecule. Substrate specificity of bacterial hyaluronate lyases varies considerably in the different species of microbe producers. Hyaluronidase of Streptococcus pneumoniae has the highest substrate specificity it hydrolyses HA alone and does not destroy other glucosami-noglycans [43]. The hyaluronate lyase, when isolated from Streptococcus pneumoniae, reaches optimal activity at pH 6.0 with the Michaelis constant with respect to HA being equal to 3.8x 10 mol/l (in terms of Michaelis-Menten kinetics) [44]. The presence of Cd3 (about 10 mM) is necessary in order to show the maximum enzyme activity. 

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It was suggested (Puhvel and Reisner, 1972) that hyaluronidase can split extracellular substances of the cell wall of sebaceous ducts and thus increase the permeability of epithelial follicles. Neuraminidase can damage cell and tissue membranes, affecting the sialic acid residues on the surface of the cells. Under the action of proteases of P. acnes, which also possesses keratinolytic activity, small chemotactic peptides are produced that may have a role in the onset of inflammation. Proteolytic activity may be significant (Ingham, 1983) in complement activation. It was shown (Ingham, 1983) that a preparation of extracellular proteases from P. acnes P-37 contained at least three types of proteases with different molecular masses. The secretion of proteinases is used as a criterion in the classification of these bacteria. 

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