Heparin Hydrolases

An e/ido-glycosidase present in rat liver lysosomes has been shown to hydrolyse heparin. Inorganic sulphate equivalent to approximately one sulphamide I. M. Gracheva, T. A. Lushchik, Yu. A. Tyrsin, and E. E. Pinchukova, Biochemistry (U.S.S.R.), 1977, 42, 1258. 

An enzyme that degrades heparan sulphate is present in human platelets. The presence of this enzyme in platelets, which do not contain endogenous heparan sulphate, suggests that platelets are able to degrade heparan sulphate in other cells e.g. endothelial cells) in the vascular space. 

A heparin-degrading enzyme isolated from a transplantable murine mastocytoma hydrolysed some of the bonds in macromolecular mastocytomal [ S]heparin, yielding products similar in size to commercial heparins.  

Ku5era and J. Hanus, Coll. Czech. Chem. Comm., 1975, 40, 2536. 

Although the linkages cleaved in macromolecular heparin were only tentatively identified, the enzyme appears to act on regions of the chain containing 2-acetamido-2-deoxy-D-glucosyl residues. D-Glucopyranosyluronic acid residues are exposed by the action of this enzyme, which is a heparin hydrolase (an endo-D-glucuronidase), 

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Glycopeptide-linkage hydrolases a-L-Guluronan lyase Heparin hydrolase Hyaluronate lyase Hyaluronidase L-Iduronic acid 2-sulphate sulphatase a-L-Iduronidase Inulinase Isoamylase Isopullulanase a-Lactalbumin Lactose synthase... 

Aldurazyme polymorphic variation of human a-L-iduronidase lysosomal hydrolase hydrolysis of terminal a-L-iduronic acid residues of dermatan sulfate and heparin sulfate No genotoxicity studies clinical trials Studies to assess mutagenic and carcinogenic potential have not been conducted No warnings or precautions regarding carcinogenic risk... 

Affinity chromatography of human liver hydrolases Fractionation of low molecular weight porcine heparin into active and relatively inactive forms Affinity chromatography of heparin Affinity chromatography of rabbit anti-thyroglobulin antibodies Purification of Phaseolus vulgaris isolectins Purification of in vivo activity of an H-Z allo-antiserum... 

Heparinized whole blood could also be subjected to digestion with the bile acid conjugate hydrolase. Except for a slightly modified extraction procedure, the same method as utilized for plasma was applied to the workup of whole blood. 

Significant differences have been observed between the interactions of several sulphate-containing glycosaminoglycans with particulate lysosomal protein, leading to inhibition of a number of lysosomal acid hydrolases. The order of levels of inhibition is heparin > chondroitin 4-sulphate = chondroitin 6-sulphate > dermatan sulphate. 

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