title: Resistance of dextran-modified hyaluronidase to inhibition by heparin.
abstract: Properties of native and aldehyde dextran-modified hyaluronidase (with surface amino group modification about 98%) were investigated. Optimal endoglycosidase activity of the native enzyme was observed at 0.15 M NaCl and pH 5.5 and electrostatic interactions influenced the enzyme activity. The inhibitory effect of heparin on hyaluronidase activity slightly differed at pH 5.5 (1.5-fold inhibition) and 7.5 (1.2-fold inhibition). Ionic strength of the reaction medium only slightly influenced the effect of heparin. Modification of hyaluronidase with dextran increased hydrophobic interactions and steric hindrance. Conjugation with dextran increased the resistance of hyaluronidase activity to denaturing agents (urea, guanidinium hydrobromide) and extended the optimal conditions for maximal endoglycosidase activity (pH 4.5-6.5, the range of NaCl concentration from 0.1 to 0.3 M). The conjugation also reduced electrostatic effects on the active site of hyaluronidase and efficacy of heparin inhibition. At pH 7.5 the enzyme was almost insensitive to heparin. The resistance of dextran-modified hyaluronidase to heparin points to approaches for subsequent studies of the heparin-binding site of this enzyme and biomedical trial of the stabilized enzyme for the treatment of acute cardiovascular lesions.
authors.affiliation: Institute of Experimental Cardiology, Russian Cardiology Research Center, Moscow, 121552, Russia. cclibr@transts.ru
authors.forename: A V
authors.initials: AV
authors.lastname: Maksimenko
authors.forename: Y V
authors.initials: YV
authors.lastname: Schechilina
authors.forename: E G
authors.initials: EG
authors.lastname: Tischenko
mesh_terms: D000818:Animals; D002384:Catalysis; D002417:Cattle; D003911:Dextrans / Q000737:chemistry*; D006493:Heparin / Q000378:metabolism* / Q000494:pharmacology; D006821:Hyaluronoglucosaminidase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D046911:Macromolecular Substances; D008297:Male; D009994:Osmolar Concentration; D011489:Protein Denaturation / Q000187:drug effects; D055672:Static Electricity; D013737:Testis / Q000201:enzymology; D014508:Urea / Q000737:chemistry / Q000494:pharmacology
chemical_list: D003911:Dextrans; D046911:Macromolecular Substances; D014508:Urea; D006493:Heparin; D006821:Hyaluronoglucosaminidase